UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549





FORM 10-K





(Mark One)

|☒ | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934.
|- | --------------------------------------------------------------------------------------

For the fiscal year ended December 31, 2017.

or



|☐ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934.
|- | ------------------------------------------------------------------------------------------

For the transition period from
 to
.





SANTANDER
DRIVE AUTO RECEIVABLES TRUST 2015-4

(Exact name of issuing entity as specified in its
charter)

Commission file number of the issuing entity:
333-192513-08

Central Index Key Number of issuing
entity: 0001649011

SANTANDER DRIVE AUTO RECEIVABLES LLC

(Exact name of depositor as specified in its charter)

Commission file number of depositor: 333-192513

Central Index Key Number of depositor: 0001383094

SANTANDER CONSUMER USA INC.

(Exact name of sponsor as specified in its charter)

Central Index Key Number of sponsor: 0001540151





Delaware

(State or other jurisdiction of incorporation or organization of the issuing entity)

61-1766174

(I.R.S. Employer Identification No. of the issuing entity)

c/o Santander Drive Auto Receivables LLC

1601 Elm Street, Suite 800

Dallas, Texas 75201

(Address of principal executive offices)

(214) 292-1930

(Telephone number, including area code)

Securities Registered Pursuant to Section 12 (b) of the Securities Exchange Act of 1934: None

Securities Registered Pursuant to Section 12 (g) of the Securities Exchange Act of 1934: None





Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities
Act.    Yes   ☐    No   ☒

Indicate by check mark if the registrant is
not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ☐    No  ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15 (d) of the Securities Exchange
Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90
days.    Yes  ☒    No  ☐

Indicate by check mark whether the registrant has
submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter)
during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ☒    No  ☐

Indicate by check mark if the disclosure of delinquent filers pursuant to Item 405 of Regulation S-K
(§229.405 of this chapter) is not contained herein and will not be contained, to the best of the Registrants knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ☒

Indicate by check
mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of accelerated filer and large accelerated filer in Rule 12b-2 of the Exchange Act. (Check one):



|                        |  |                                                  |  |                           |  |  
|----------------------- |  | ------------------------------------------------ |  | ------------------------- |  | -
|Large accelerated filer |  | ☐                                                |  | Accelerated filer         |  | ☐
|                        |  |                                                  | 
|Non-accelerated filer   |  | ☒  (Do not check if a smaller reporting company) |  | Smaller reporting company |  | ☐
|                        |  |                                                  | 
|                        |  |                                                  |  | Emerging growth company   |  | ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period
for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.   ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the
Act).    Yes  ☐    No  ☒

State the aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common
equity, as of the last business day of the registrants most recently completed second fiscal quarter. Not applicable.

List hereunder the
following documents if incorporated by reference and the part of the Form 10-K (e.g. Part I, Part II, etc.) into which the document is incorporated: (1) Any annual report to security holders; (2) Any
proxy information statement; and (3) Any prospectus filed pursuant to Rule 424(b) or (c) under the Securities Act of 1933. The listed documents should be clearly described for identification purposes (e.g., annual report to security
holders for fiscal year ended December 24, 1980). None.









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PART I

The following items have been omitted in accordance with General Instruction J to Form 10-K:

Item 1: Business

Item 1A: Risk Factors

Item 2: Properties

Item 3: Legal Proceedings

Item 4: Mine Safety Disclosures



|Item 1B. | Unresolved Staff Comments.
|-------- | --------------------------

Nothing to report.

Substitute information provided in accordance with General Instruction J to Form 10-K:

Item 1112(b) of Regulation AB. Significant Obligors of Pool Assets (Financial Information).

Nothing to report.

Item 1114(b)(2) of
Regulation AB. Credit Enhancement and Other Support, Except for Certain Derivatives Instruments (Information Regarding Significant Enhancement Providers).

Nothing to report.

Item 1115(b) of
Regulation AB. Certain Derivatives Instruments (Financial Information).

Nothing to report.

Item 1117 of Regulation AB. Legal Proceedings.

Wells Fargo Bank, N.A., as the indenture trustee, has provided the following information:

On June 18, 2014, a group of institutional investors filed a civil complaint in the Supreme Court of the State of New York, New York
County, against Wells Fargo Bank, N.A., (Wells Fargo Bank) in its capacity as trustee under 276 residential mortgage backed securities (RMBS) trusts, which was later amended on July 18, 2014, to increase the number of
trusts to 284 RMBS trusts. On November 24, 2014, the plaintiffs filed a motion to voluntarily dismiss the state court action without prejudice. That same day, a group of institutional investors filed a putative class action complaint in the
United States District Court for the Southern District of New York (the District Court) against Wells Fargo Bank, alleging claims against the bank in its capacity as trustee for 274 RMBS trusts (the Federal Court Complaint).
In December 2014, the plaintiffs motion to voluntarily dismiss their original state court action was granted. As with the prior state court action, the Federal Court Complaint is one of six similar complaints filed contemporaneously against
RMBS trustees (Deutsche Bank, Citibank, HSBC, Bank of New York Mellon and US Bank) by a group of institutional investor plaintiffs. The Federal Court Complaint against Wells Fargo Bank alleges that the trustee caused losses to investors and asserts
causes of action based upon, among other things, the trustees alleged failure to: (i) notify and enforce repurchase obligations of mortgage loan sellers for purported breaches of representations and warranties, (ii) notify investors
of alleged events of default, and (iii) abide by appropriate standards of care following alleged events of default. Relief sought includes money damages in an unspecified amount, reimbursement of expenses, and equitable relief. Other cases
alleging similar causes of action have been filed against Wells Fargo Bank and other trustees in the District Court by RMBS investors in these and other transactions, and these cases against Wells Fargo Bank are proceeding before the same District
Court judge. A similar complaint was also filed May 27, 2016 in New York state court by a different plaintiff investor. On January 19, 2016, an order was entered in connection with the Federal Court Complaint in which the District Court
declined to exercise jurisdiction over 261 trusts at issue in the Federal Court Complaint; the District Court also allowed plaintiffs to file amended complaints as to the remaining, non-dismissed trusts, if
they so chose, and three amended complaints have been filed. On December 17, 2016, the investor plaintiffs in the 261 trusts dismissed from the Federal Court Complaint filed a new complaint in New York state court (the State Court
Complaint). In September 2017, Royal Park Investments SA/NV (Royal Park), one of the plaintiffs in the District Court cases against Wells Fargo Bank, filed a putative class action complaint relating to two trusts seeking
declaratory and injunctive relief and money damages based on Wells Fargo Banks indemnification from trust funds for legal fees and expenses Wells Fargo Bank incurs or has incurred in defending the District Court case filed by Royal Park. With
respect to the foregoing litigations, Wells Fargo Bank believes plaintiffs claims are without merit and intends to contest the claims vigorously, but there can be no assurances as to the outcome of the litigations or the possible impact of the
litigations on Wells Fargo Bank or the RMBS trusts.

There can be no assurances as to the outcome of the litigation, or the possible impact
of the litigation on the trustee or the RMBS trusts. However, Wells Fargo Bank denies liability and believes that it has performed its obligations under the RMBS trusts in good faith, that its actions were not the cause of any losses to investors,
and that it has meritorious defenses, and it intends to contest the plaintiffs claims vigorously.



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PART II

The following items have been omitted in accordance with General Instruction J to Form 10-K:

Item 5: Market for Registrants Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Item 6: Selected Financial Data

Item 7: Managements Discussion and Analysis of Financial Condition and Results of Operations

Item 7A: Quantitative and Qualitative Disclosures about Market Risk

Item 8: Financial Statements and Supplementary Data

Item 9: Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A: Controls and Procedures



|Item 9B. | Other Information.
|-------- | ------------------

Santander Consumer USA Inc. (SC) is a wholly-owned
subsidiary of Santander Consumer USA Holdings Inc. (SC Holdings). On February 28, 2018, SC Holdings filed its Annual Report on Form 10-K for the year ended December 31, 2017 and disclosed
certain legal and regulatory matters. Additional information about SC Holdings and its consolidated subsidiaries, including information contained in required annual reports on Form 10-K, quarterly reports
on Form 10-Q and current reports on Form 8-K, is on file with the SEC under the name Santander Consumer USA Holdings Inc. and file number 001-36270.

SC acts as the servicer for the issuing entity. Under the Servicing Agreement, dated
July 15, 2016, by and between SC and Santander Consumer International Puerto Rico LLC (the Subservicer), and the related Program Portfolio Schedule (the Program Portfolio Schedule, together with the Servicing Agreement, the
Subservicing Agreement), the Subservicer managed, serviced, collected, enforced, administered and provided other services with respect to each receivable held by the issuing entity that was a Performing Loan (as defined in the
Subservicing Agreement). Pursuant to the written agreement of SC and the Subservicer, the Subservicing Agreement was terminated effective on December 31, 2017 at 11:59 p.m.

SC, as sole equity member, entered into a First Amendment, dated as of February 28, 2017, to the Amended and Restated Limited Company
Agreement of Santander Drive Auto Receivables LLC, the depositor, amending the definition of independent director. The First Amendment is attached as an exhibit to this Form 10-K.

On April 13, 2017, a First Amendment to Sale and Servicing Agreement was entered into amending the definition of Liquidation Proceeds in
the Sale and Servicing Agreement. The Second Amendment is attached as an exhibit to this Form 10-K.



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PART III

The following items have been omitted in accordance with General Instruction J to Form 10-K:

Item 10: Directors, Executive Officers, and Corporate Governance

Item 11: Executive Compensation

Item 12: Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13: Certain Relationships and Related Transactions, and Director Independence

Item 14: Principal Accounting Fees and Services

Substitute information provided in accordance with General Instruction J to Form 10-K:

Item 1119 of Regulation AB. Affiliations and Certain Relationships and Related Transactions.

Information required by Item 1119 of Regulation AB has been omitted from this report on Form 10-K in
reliance on the Instruction to Item 1119.

Item 1122 of Regulation AB. Compliance with Applicable Servicing Criteria.

Each of SC, the Subservicer and Wells Fargo Bank, National Association (each, a Servicing Participant) have been identified by the
issuing entity as parties participating in the servicing function with respect to the pool assets held by the issuing entity. Each of the Servicing Participants has completed a report on an assessment of compliance with the servicing criteria
applicable to it (each, a Report on Assessment), which Reports on Assessment are attached as exhibits to this Form 10-K. In addition, each of the Servicing Participants has provided an
attestation report (each, an Attestation Report) by one or more registered public accounting firms, which reports are also attached as exhibits to this Form 10-K.

Managements Assessment of Compliance for SC has identified material instances of noncompliance for the 2017 fiscal year, one of which is
a continuation of a material instance of noncompliance reported by the issuing entity in its annual report on Form 10-K filed March 30, 2017 and relates to reports to investors delivered during or prior
to March 2017.

Managements Assessment of Compliance for SC for the 2016 fiscal year identified a material instance of noncompliance
related to the servicing criterion set forth in Item 1122(d)(3)(i)  reports to investors, including those to be filed with the Commission, were not maintained in accordance with the transaction agreements and applicable Commission
requirements. Specifically, reports to investors provided information that was not calculated in accordance with the terms specified in the transaction agreements. SC determined the existence of a material instance of noncompliance in March 2017,
and the material instance of noncompliance related to this instance for the 2017 fiscal year relates to reports to investors delivered during or prior to March 2017. The instance of noncompliance described in this paragraph for both the 2016 and
2017 fiscal years, which does relate to the asset-backed securities covered in this Form 10-K and issued by the issuing entity, relates to two separate matters:

Under the transaction agreements for the Platform, SC, as Servicer, is entitled to receive all Supplemental Servicing Fees as additional
servicing compensation, and such Supplemental Servicing Fees do not constitute Available Funds. However, SC included Supplemental Servicing Fees for certain transactions in the Platform under other amounts received and included such
amounts as part of Available Funds in the investor reports; for these transactions, Supplemental Servicing Fees were distributed in accordance with the payment priorities set forth in the related transaction agreements rather than being
retained by the Servicer.



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---

To address this issue related to Supplemental Servicing Fees and the related instance of
noncompliance, SC stopped including Supplemental Servicing Fees as other amounts received for all transactions in the Platform beginning with the March 2017 collection period and began retaining such amounts as additional servicing
compensation as specified in the transaction agreements. SC believes that the inclusion of Supplemental Servicing Fees as available funds did not result in any material adverse effect on security holders.

Under the transaction agreements for the Platform, SC, as Servicer, is required to pay all expenses incurred by it in connection with its
activities as servicer other than expenses in connection with the sale of a repossessed vehicle, which may be netted from liquidation proceeds from such sale. For certain transactions in the Platform, SC did not net external costs associated
with repossession expenses attributable to financed vehicles sold after the related receivables have become defaulted receivables; for these transactions, SC paid such repossession expenses and the Liquidation Proceeds included in the
investor reports and distributed in accordance with the payment priorities set forth in the related transaction agreements were greater than they would have been had SC reduced the liquidation proceeds by the external costs associated with
repossession expenses in accordance with the transaction agreements for those transactions.

To address this issue related to repossession
expenses and the related instance of noncompliance, SC amended the transaction agreements for the effected transactions in the Platform to memorialize the agreement of the Servicer to pay such external costs of repossessions rather than netting such
amounts from sale proceeds from the disposition of repossessed financed vehicles. SC believes that the payment of external costs associated with repossession expenses by the Servicer and the failure to report Liquidation Expenses on the
investor reports net of such repossession expenses for certain transactions did not result in any material adverse effect on security holders.

Managements Assessment of Compliance for SC for the 2017 fiscal year identified an additional matter that resulted in a finding of a
material instance of noncompliance related to the servicing criterion set forth in Item 1122(d)(3)(i)  reports to investors, including those to be filed with the Commission, were not maintained in accordance with the transaction agreements and
applicable Commission requirements and Item 1122(d)(4)(iii)  any additions, removals or substitutions to the asset pool are made, reviewed and approved in accordance with any conditions or requirements in the transaction agreements. This
matter relates to the following circumstance:

The transaction agreements for each transaction in the Platform specify the repurchase price
to be paid by SC in connection with the repurchase of receivables from the issuing entity. In August 2017, the Servicer recalculated the accrued interest portion of the repurchase price paid in connection with the prior repurchase of receivables
from issuers included in the Platform and, after recalculating the amount of accrued interest owed, determined that there was an aggregate shortfall in the repurchase price paid for certain of the transactions in the Platform. The material instance
of noncompliance described in this paragraph does relate to the asset-backed securities covered by this Form 10-K and issued by the issuing entity.

To address this issue related to the repurchase price for receivables and the related instances of noncompliance, SC recalculated the
repurchase price for all affected transactions and made deposits on August 15, 2017 into the applicable collection account in an amount equal to the shortfall. Additionally, SC updated the related systems coding applicable to the methodology
for calculating the repurchase price in August 2017 to avoid future shortfalls. SC believes that the shortfall in the accrued interest portion of the repurchase price paid in connection with the prior repurchase of receivables and the subsequent
deposit of the shortfall into the applicable collection account did not result in any material adverse effect on security holders.



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With respect to the instances of noncompliance described above, SC has implemented additional
procedures to confirm that calculations included in investor reports are completed as set forth in the transaction agreements and has implemented greater management oversight of reporting, enhanced quality assurance controls, and updated the related
systems coding applicable to calculations included in investor reports.

Item 1123 of Regulation AB. Servicer Compliance
Statements.

SC and the Subservicer have been identified by the issuing entity as the servicers with respect to the asset pool held by
the issuing entity. Each of SC and the Subservicer have completed a statement of compliance with applicable servicing criteria (each, a Compliance Statement) signed by an authorized officer. The Compliance Statements are
attached as exhibits to this Form 10-K.



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PART IV

Item 15. Exhibits and Financial Statement Schedules.

(a)(1)     Not Applicable.

(a)(2)
    Not Applicable.

(a)(3)     See Item 15(b) below.

(b)         Exhibits.

The exhibits listed below are either included or incorporated by reference as indicated:



|            |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|----------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit No. |  | Description                                                                                                                                                                                                                                                                                                                                                                                                                                              
|            | 
|1.1         |  | Underwriting Agreement, dated as of August 
20, 2015, among Santander Drive Auto Receivables LLC (Santander Drive), Santander Consumer USA Inc. (SC) and Wells Fargo Securities, LLC and Citigroup Global Markets Inc., as representatives of the several underwriters (incorporated
 by reference to Exhibit 1.1 of Form 8-K filed by the Issuer (Commission File No. 333-192513-08) with the Securities and
Exchange Commission on August 24, 2015)
|            | 
|3.1         |  | Amended and Restated Limited Liability Company Agreement of Santander Drive dated as of March 
7, 2007 (incorporated by reference to Exhibit 3.1 of Form S-3 filed by Santander Drive (Commission File No. 
333-192513) with the Securities and Exchange Commission on November 22, 2013)                                                                                                                                                                
|            | 
|3.2         |  | First Amendment to Amended and Restated Limited Liability Company Agreement, dated as of February 
28, 2017, by SC, as sole equity member (incorporated by reference to Exhibit 3.1 of Form 8-K filed by the Santander Drive (Commission File No. 
333-139609) with the Securities and Exchange Commission on March 1, 2017)                                                                                                                             
|            | 
|4.1         |  | Indenture, dated as of August 
26, 2015, between Santander Drive Auto Receivables Trust 2015-4, as issuer (the Issuer), and Wells Fargo Bank, National Association, as indenture trustee (the Indenture Trustee) (incorporated
 by reference to Exhibit 4.1 of Form 8-K filed by the Issuer (Commission File No. 333-192513-08) with the Securities and
Exchange Commission on August 27, 2015)                                                      
|            | 
|10.1        |  | Purchase Agreement, dated as of August 26, 2015, between SC and Santander Drive (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the Issuer (Commission File No. 333-192513-08) with the Securities and Exchange Commission on August 27, 2015)                                                                                                                                                                                           
|            | 
|10.2        |  | Sale and Servicing Agreement, dated as of August 
26, 2015, among the Issuer, Santander Drive, SC and the Indenture Trustee (incorporated by reference to Exhibit 10.2 of Form 8-K filed by the Issuer (Commission File No. 333-192513-08) with the Securities and Exchange Commission on August 27, 2015)                                                                                                                                               
|            | 
|10.3        |  | Administration Agreement, dated as of August 
26, 2015, among the Issuer, SC, as administrator, and the Indenture Trustee (incorporated by reference to Exhibit 10.3 of Form 8-K filed by the Issuer (Commission File No. 333-192513-08) with the Securities and Exchange Commission on August 27, 2015)                                                                                                                                                 



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|     |  |                                                                                                                                                                                                                                                                                                                                                                                                  
|---- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|     | 
|10.4 |  | Amended and Restated Trust Agreement, dated as of August 
26, 2015, between Santander Drive and Wilmington Trust, National Association, not in its individual capacity but solely as owner trustee for the Issuer (incorporated by reference to Exhibit 10.4 of Form 8-K filed
 by the Issuer (Commission File No. 333-192513-08) with the Securities and Exchange Commission on August 27, 2015)
|     | 
|10.5 |  | First Amendment to Sale and Servicing Agreement, dated April 13, 2017 (incorporated by reference to Exhibit 10.2 of Form 10-D filed by the Issuer (Commission File No. 333-192513-08) with the Securities and Exchange Commission on April 17, 2017)                                                                                                                                             
|     | 
|31.1 |  | Certification (Santander Drive)                                                                                                                                                                                                                                                                                                                                                                  
|     | 
|33.1 |  | Managements Assessment of Compliance with SEC Regulation AB Servicing Criteria (SC)                                                                                                                                                                                                                                                                                                             
|     | 
|33.2 |  | Assessment of Compliance with the Applicable Servicing Criteria (Indenture Trustee)                                                                                                                                                                                                                                                                                                              
|     | 
|33.3 |  | Managements Assessment of Compliance with SEC Regulation AB Servicing Criteria (Subservicer)                                                                                                                                                                                                                                                                                                    
|     | 
|34.1 |  | Report of Independent Registered Public Accounting Firm (PricewaterhouseCoopers LLP with respect to SC)                                                                                                                                                                                                                                                                                          
|     | 
|34.2 |  | Report of Independent Registered Public Accounting Firm (KPMG LLP with respect to the Indenture Trustee)                                                                                                                                                                                                                                                                                         
|     | 
|34.3 |  | Report of Independent Registered Public Accounting Firm (PricewaterhouseCoopers LLP with respect to the Subservicer)                                                                                                                                                                                                                                                                             
|     | 
|35.1 |  | Servicer Compliance Statement (SC)                                                                                                                                                                                                                                                                                                                                                               
|     | 
|35.2 |  | Servicer Compliance Statement (Subservicer)                                                                                                                                                                                                                                                                                                                                                      
|     | 
|99.1 |  | Servicing Agreement, dated as of July 
15, 2016, by and between SC and Santander Consumer International Puerto Rico LLC (the Subservicer) (incorporated by reference to Exhibit 99.1 of Form 8-K filed by Santander Drive (Commission File No. 333-139609) with the Securities and Exchange Commission on March 1, 2017)                                                                       
|     | 
|99.2 |  | Amended and Restated Program Portfolio Schedule (SDART Publicly Registered Transactions), dated as of January 
31, 2017, by and between SC and the Subservicer (incorporated by reference to Exhibit 99.2 of Form 8-K filed by Santander Drive (Commission File No. 
333-139609) with the Securities and Exchange Commission on March 1, 2017)                                                   



|(c) | Not Applicable.
|--- | ---------------

Supplemental information to be Furnished With Reports Filed Pursuant to Section 15(d)
of the Act by Registrants Which Have Not Registered Securities Pursuant to Section 12 of the Act.

No annual report, proxy statement, form of
proxy or other proxy soliciting material has been sent to certificateholders, and the registrant does not presently contemplate sending any such materials subsequent to the filing of this report.



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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to
be signed on its behalf by the undersigned, thereunto duly authorized.

Date: March 30, 2018



SANTANDER DRIVE AUTO RECEIVABLES LLC, as depositorBy:

/s/ Corey HenryName:

Corey HenryTitle:

President and Chief Executive Officer(senior officer in charge of securitization of the depositor)




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