**Exhibit 99.1**     **Volkswagen Auto Loan Enhanced Trust 2003-1** **MONTHLY SERVICER CERTIFICATE**  **For the collection period ended 12-26-2005******              ***A.*** ***DATES*** *Begin* *End* *# days* 1 Determination Date   1/18/2006              2 Payment Date   1/20/2006              3 Collection Period 11/27/2005 12/26/2005 30        4 Monthly Interest Period - Actual/360 12/20/2005 1/19/2006 31        5 Monthly Interest - 30/360     30   
***B. SUMMARY***                            ***Initial Balance***  ***Beginning Balance***  ***Principal Payment***  ***Ending Balance***  ***Note Factor*** 6 Class A-1 Notes   315,000,000.00    —   —   —   — 7 Class A-2 Notes   370,000,000.00   —   —   —   — 8 Class A-3 Notes   385,000,000.00    81,832,157.07    18,714,310.65    63,117,846.42    0.1639425 9 Class A-4 Notes   214,173,000.00    214,173,000.00   —    214,173,000.00    1.0000000 10 Class B Notes   29,559,766.00    29,559,766.00   —    29,559,766.00    1.0000000    11 **Total Securities** **$****1,313,732,766.00**  **$****325,564,923.07**  **$****18,714,310.65**  **$****306,850,612.42**                                  12 **Net Pool Balance** **$****1,334,414,493.82**  **$****329,979,854.28**      **$****310,954,582.38**                                           ***Per $1000*** ***Principal & Interest*** ***Per $1000***    ***Coupon Rate*** ***Interest Pmt Due*** ***Face Amount*** ***Payment Due*** ***Face Amount***                  13 Class A-1 Notes  1.0050%  —   —   —   — 14 Class A-2 Notes  1.1100%  —   —   —   — 15 Class A-3 Notes  1.4900%   101,608.26    1.2416667    18,815,918.91    229.9330677 16 Class A-4 Notes  1.9300%   344,461.58    1.6083333    344,461.58    1.6083333      **Total Securities**      **446,069.84**       **19,160,380.49**                                      ***C.*** ***COLLECTIONS AND AVAILABLE FUNDS***     17 Scheduled Principal Payments Received   13,163,162.24 18 Scheduled Interest Payments Received   1,030,200.64 19 Prepayments of Principal Received   109,958.90 20 Liquidation Proceeds   5,557,471.45 21 Recoveries Received   190,440.39 22 Other Payments Received to Reduce Principal  —    23 **Subtotal: Total Collections**   20,051,233.62    24 Repurchased Receivables  — 25 Reserve Account Excess Amount (Item 85)   34,001.04    26 **Total Available Funds, prior to Servicer Advances**   20,085,234.66    27 Servicer Advance (Item 68)  —    28 **Total Available Funds + Servicer Advance**   20,085,234.66    29 Reserve Account Draw Amount (Item 71)  —    30 **Total Available Funds + Servicer Advance and Reserve Account Draw Amount**   20,085,234.66           ***D.*** ***DISTRIBUTIONS***       **Distribution Summary:**    31 Prior Advance Reimbursement (Item 74)  — 32 Servicing Fees (Item 38)   271,304.10 33 Class A Noteholder Interest (Item 47)   446,069.84 34 Principal Distribution Amount (Item 72)   18,714,310.65 35 Amount Paid to Reserve Account to Reach Specified Balance  — 36 Other Amounts Paid to Trustees  —    37 **Remaining Funds to Certificateholder**   653,550.07    

 
     **Volkswagen Auto Loan Enhanced Trust 2003-1** **MONTHLY SERVICER CERTIFICATE**  **Forthe collection period ended 12-26-2005****** **PAGE 2**                  **Distribution Detail:** *Due*  *Shortfall*  *Paid*    38 Servicing Fees   271,304.10   —   271,304.10                     Pro rata:            39 Class A-1 Interest  —   —   — 40 Class A-2 Interest  —   —   — 41 Class A-3 Interest   101,608.26   —    101,608.26 42 Class A-4 Interest   344,461.58   —    344,461.58 43 Class A-1 Interest Carryover Shortfall  —   —   — 44 Class A-2 Interest Carryover Shortfall  —   —   — 45 Class A-3 Interest Carryover Shortfall  —   —   — 46 Class A-4 Interest Carryover Shortfall  —   —   —    47 Class A Noteholder Interest   446,069.84   —    446,069.84                   *E.* ***CALCULATIONS***               **Calculation of Principal Distribution Amount:**            48 Beginning Note Balance - All Classes           325,564,923.07 49 Beginning Net Pool Balance       329,979,854.28     50 Receipts of Scheduled Principal       (13,163,162.24)    51 Receipts of Prepaid Principal       (109,958.90)    52 Liquidation Proceeds       (5,557,471.45)    53 Other Collections of Principal      —     54 Principal Amount of Repurchases      —     55 Principal Amount of Defaulted and Terminated Receivables       (194,679.31)                  56 Ending Net Pool Balance       310,954,582.38     57 Yield Supplement Overcollateralization Amount       4,103,969.96                   58 Adjusted Pool Balance       306,850,612.42     59 Less: Adjusted Pool Balance - End of Collection Period           306,850,612.42    60 **Calculated Principal Distribution Amount**           18,714,310.65                     **Calculation of Servicer Advance:**            61 Available Funds, prior to Servicer Advances (Item 26)           20,085,234.66 62 Less: Prior Advance Reimbursement (Item 31)          — 63 Less: Servicing Fees Paid (Item 32)           271,304.10 64 Less: Interest Paid to Noteholders (Item 33)           446,069.84 65 Less: Calculated Principal Distribution (Item 60)           18,714,310.65    66 Equals: Remaining Available Funds before Servicer Advance           653,550.07 67 Monthly Loan Payments Due on Included Units but not received (N/A if Item 66 > 0)       N/A    68 **Servicer Advance (If Item 66 < 0, lesser of Item 66 and Item 67, else 0)**          —                     **Calculation of Reserve Account Draw Amount:**            69 Remaining Available Funds, before Reserve Account Draw (Item 66 plus Item 68)        653,550.07 70 Available Funds Shortfall Amount (If Item 69 < 0, Item 69, else 0)          —    71 **Reserve Account Draw Amount (If Item 70 is > 0, Lesser of Reserve Acct Balance and Item 70)**   —                      72 **Principal Distribution Amount (Item 60 - Available Funds Shortfall + Reserve Account Draw Amt)**    18,714,310.65                     **Reconciliation of ServicerAdvance:**            73 Beginning Balance of Servicer Advance          — 74 Less: Prior Advance Reimbursement          — 75 Plus: Additional Payment Advances for Current Period          —    76 Ending Balance of Payment Advance          —    

 
     **Volkswagen Auto Loan Enhanced Trust 2003-1** **MONTHLY SERVICER CERTIFICATE**  **Forthe collection period ended 12-26-2005****** **PAGE 3**            ***F.*** ***RESERVE ACCOUNT***           **Reserve Account Balances:**        77 Specified Reserve Account Balance       9,852,995.74 78 Initial Reserve Account Balance       6,568,663.83            79 Beginning Reserve Account Balance       9,852,995.74 80 Plus:  Net Investment Income for the Collection Period       34,001.04    81 Subtotal:  Reserve Fund Available for Distribution       9,886,996.78 82 Plus:  Deposit of Excess Available Funds (Item 35)      — 83 Less:  Reserve Account Draw Amount (Item 71)      —    84 Subtotal Reserve Account Balance       9,886,996.78 85 Less: Reserve Account Excess Amount to Available Funds (If Item 84 > Item 77)       34,001.04    86 **Equals: Ending Reserve Account Balance**       9,852,995.74               87 **Change in Reserve Account Balance from Immediately Preceding Payment Date**      —               ***G.*** ***POOL STATISTICS***           **Collateral PoolBalance Data:** ***Initial*** *Current*          88 Net Pool Balance   1,334,414,494           310,954,582 89 Number of Current Contracts   74,039    37,698 90 Weighted Average Loan Rate  4.21%  4.00%91 Average Remaining Term  51.9    24.3  92 Average Original Term  55.6   59.3                         **Net Credit Lossand Repossession Activity:** ***Units***  ***Outstanding***