Exhibit 5.1

Volkswagen Auto Lease/Loan

Underwritten Funding, LLC

2200 Ferdinand Porsche Drive

Herndon, Virginia 20171

Registration Statement on Form SF-3 (No. 333-205992)

Ladies and Gentlemen:

We have acted as special counsel to Volkswagen Auto Lease/Loan Underwritten Funding, LLC (the “Company”), a Delaware limited liability company, in connection with the above-captioned registration statement (such registration statement, together with the exhibits and any amendments thereto, the “Registration Statement”) filed by the Company with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”) and the offering of the Class A-1 Asset Backed Notes, the Class A-2-A Asset Backed Notes, the Class A-2-B Asset Backed Notes, the Class A-3 Asset Backed Notes and the Class A-4 Asset Backed Notes (collectively, the “Notes”) described in the final prospectus dated November 15, 2018 (the “Prospectus”), which has been filed with the Commission pursuant to Rule 424(b)(5) under the Securities Act of 1933, as amended (the “Act”). As described in the Prospectus, the Notes will be issued by Volkswagen Auto Loan Enhanced Trust 2018-2 (the “Issuer”), a trust formed by the Company pursuant to a trust agreement among the Company, Citibank, N.A., as owner trustee, and Citicorp Trust Delaware, National Association, as issuer Delaware trustee. The Notes will be issued pursuant to an indenture between the Issuer and Deutsche Bank Trust Company Americas, as indenture trustee (the “Indenture Trustee”). Capitalized terms used herein without definition have the respective meanings assigned to such terms in the Prospectus.

In that regard, we generally are familiar with the proceedings taken or required to be taken in connection with the proposed authorization, issuance and sale of the Notes, and have examined and relied upon copies of such statutes, documents, corporate records and other instruments as we have deemed necessary or appropriate for the purposes of this opinion, including the Prospectus and current drafts of the Indenture (including the form of the Notes included as an exhibit thereto), the Amended and Restated Trust Agreement (including the form of Certificate included as an exhibit thereto), the Receivables Purchase Agreement, the Sale and Servicing Agreement, the Asset Representations Review Agreement and the Administration Agreement (collectively the “Transaction Documents”).

Based on and subject to the foregoing, we are of the opinion that, with respect to the Notes, when (a) the Indenture has been duly qualified under the Trust Indenture Act of 1939, as

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Volkswagen Auto Lease/Loan

Underwritten Funding, LLC

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amended, (b) the Notes have been duly executed and issued by the Issuer, authenticated by the Indenture Trustee, and sold by the Seller, and (c) payment of the agreed consideration for the Notes shall have been received by the Issuer, all in accordance with the terms and conditions of the related Transaction Documents and a definitive purchase, underwriting or similar agreement with respect to the Notes and in the manner described in the Prospectus, the Notes will have been duly authorized by all necessary action of the Issuer and will be legally issued and binding obligations of the Issuer and entitled to the benefits afforded by the Indenture, except as may be limited by bankruptcy, insolvency, reorganization, arrangement, moratorium or other laws relating to or affecting creditors’ rights generally (including, without limitation, fraudulent conveyance laws), and by general principles of equity, regardless of whether such matters are considered in a proceeding in equity or at law.

Our opinions expressed herein are limited to the federal laws of the United States and the laws of the State of New York and the State of Delaware. We hereby consent to the filing of this opinion with the Commission as Exhibit 5.1 to a Form 8-K filed in connection with the Prospectus and to the use of our name therein without admitting we are “experts” within the meaning of the Act or the rules and regulations of the Commission issued thereunder, with respect to any part of the Registration Statement or the Prospectus.

Very truly yours,

/s/ Mayer Brown LLP

MAYER BROWN LLP