**Exhibit 99.1**     **Volkswagen Auto Loan Enhanced Trust 2003-1** **MONTHLY SERVICER CERTIFICATE**  **For the collection period ended 4-29-2006****Data Current as of 5/2/2006 01:49:24 PM**              ***A.*** ***DATES*** *Begin* *End* *# days* 1 Determination Date   5/18/2006              2 Payment Date   5/22/2006              3 Collection Period 4/1/2006 4/29/2006 29        4 Monthly Interest Period - Actual/360 4/20/2006 5/21/2006 32        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   303,929.73   303,929.73   —   — 9 Class A-4 Notes  214,173,000.00   214,173,000.00   17,153,049.40   197,019,950.60   0.9199103 10 Class B Notes  29,559,766.00   29,559,766.00   —   29,559,766.00   1.0000000    11 **Total Securities** **$****1,313,732,766.00**  **$****244,036,695.73**  **$****17,456,979.13**  **$****226,579,716.60**                                  12 **Net Pool Balance** **$****1,334,414,493.82**  **$****247,283,103.76**      **$****229,564,389.21**                                           ***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%  377.38   1.2416667   304,307.11   1,001.2416667 16 Class A-4 Notes  1.9300%  344,461.58   1.6083333   17,497,510.97   81.6980244      **Total Securities**      **344,838.95**       **17,801,818.08**                                      ***C.*** ***COLLECTIONS AND AVAILABLE FUNDS***     17 Scheduled Principal Payments Received  11,380,885.59 18 Scheduled Interest Payments Received  761,339.66 19 Prepayments of Principal Received  75,689.71 20 Liquidation Proceeds  6,128,909.46 21 Recoveries Received  97,374.63 22 Other Payments Received to Reduce Principal  —    23 **Subtotal: Total Collections**  18,444,199.05    24 Repurchased Receivables  — 25 Reserve Account Excess Amount (Item 85)  37,347.75    26 **Total Available Funds, prior to Servicer Advances**  18,481,546.80    27 Servicer Advance (Item 68)  —    28 **Total Available Funds + Servicer Advance**  18,481,546.80    29 Reserve Account Draw Amount (Item 71)  —    30 **Total Available Funds + Servicer Advance and Reserve Account Draw Amount**  18,481,546.80           ***D.*** ***DISTRIBUTIONS***       **Distribution Summary:**    31 Prior Advance Reimbursement (Item 74)  — 32 Servicing Fees (Item 38)  203,363.91 33 Class A Noteholder Interest (Item 47)  344,838.95 34 Principal Distribution Amount (Item 72)  17,456,979.13 35 Amount Paid to Reserve Account to Reach Specified Balance  — 36 Other Amounts Paid to Trustees  —    37 **Remaining Funds to Certificateholder**  476,364.80    

 
     **Volkswagen Auto Loan Enhanced Trust 2003-1** **MONTHLY SERVICER CERTIFICATE**  **Forthe collection period ended 4-29-2006****** **PAGE 2**               **Distribution Detail:** *Due*  *Shortfall*  *Paid*    38 Servicing Fees  203,363.91   —   203,363.91                  Pro rata:         39 Class A-1 Interest  —   —   — 40 Class A-2 Interest  —   —   — 41 Class A-3 Interest  377.38   —   377.38 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  344,838.95   —   344,838.95                ***E.*** ***CALCULATIONS***            **Calculation of Principal Distribution Amount:**         48 Beginning Note Balance - All Classes        244,036,695.73 49 Beginning Net Pool Balance     247,283,103.76    50 Receipts of Scheduled Principal     (11,380,885.59)   51 Receipts of Prepaid Principal     (75,689.71)   52 Liquidation Proceeds     (6,128,909.46)   53 Other Collections of Principal     —    54 Principal Amount of Repurchases     —    55 Principal Amount of Defaulted and Terminated Receivables     (133,229.79)               56 Ending Net Pool Balance     229,564,389.21    57 Yield Supplement Overcollateralization Amount     2,984,672.61                58 Adjusted Pool Balance     226,579,716.60    59 Less: Adjusted Pool Balance - End of Collection Period        226,579,716.60    60 **Calculated Principal Distribution Amount**        17,456,979.13                  **Calculation of Servicer Advance:**         61 Available Funds, prior to Servicer Advances (Item 26)        18,481,546.80 62 Less: Prior Advance Reimbursement (Item 31)        — 63 Less: Servicing Fees Paid (Item 32)        203,363.91 64 Less: Interest Paid to Noteholders (Item 33)        344,838.95 65 Less: Calculated Principal Distribution (Item 60)        17,456,979.13    66 Equals: Remaining Available Funds before Servicer Advance        476,364.80 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)      476,364.80 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)**   17,456,979.13                  **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 4-29-2006****** **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     37,347.75    81 Subtotal:  Reserve Fund Available for Distribution     9,890,343.49 82 Plus:  Deposit of Excess Available Funds (Item 35)     — 83 Less:  Reserve Account Draw Amount (Item 71)     —    84 Subtotal Reserve Account Balance     9,890,343.49 85 Less: Reserve Account Excess Amount to Available Funds (If Item 84 > Item 77)     37,347.75    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   229,564,389 89 Number of Current Contracts  74,039   32,281 90 Weighted Average Loan Rate  4.21%  3.95%91 Average Remaining Term  51.9   20.7 92 Average Original Term  55.6   59.6                          ***Outstanding***  **Net Credit Lossand Repossession Activity:** ***Units***  ***Principal Balance***        93 Aggregate Outstanding Principal Balance of Charged Off Receivables  15   133,230 94 Liquidation Proceeds on Related Vehicles     — 95 Recoveries Received on Receivables Previously Charged Off     97,375    96 Net Principal Losses for Current Collection Period  15   35,855    97 Beginning Net Principal Losses  849   5,918,146 98 Net Principal Losses for Current Collection Period  15   35,855    99 Cumulative Net Principal Losses  864   5,954,001                          ***Outstanding***  **DelinquenciesAging Profile - End of Period:** ***Percentage*** ***Units***  ***PrincipalBalance***            100 Current  99.01%  31,985   227,301,357 101 31 - 60 Days Delinquent  0.90%  272   2,065,100 102 61 - 90 Days Delinquent  0.09%  24   197,932    103 **Total**  100.00%  32,281  229,564,389