Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Blair John Allen
  2. Issuer Name and Ticker or Trading Symbol
DealerTrack Holdings, Inc. [TRAK]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
* Please see below
(Last)
(First)
(Middle)
C/O DEALERTRACK HOLDINGS, INC., 1111 MARCUS AVENUE, SUITE M04
3. Date of Earliest Transaction (Month/Day/Year)
12/16/2005
(Street)

LAKE SUCCESS, NY 11042
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 12/16/2005   C   979,919 A (1) 979,919 (2) I By DJR US, LLC (3)
Common Stock 12/16/2005   C   316,749 A (4) 1,296,668 (2) I By DJR US, LLC (3)
Common Stock 12/16/2005   S   289,046 D $ 15.81 1,007,622 (2) I By DJR US, LLC (3)
Common Stock 12/16/2005   P   150 A $ 17 59,086 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Convertible Series A-1 Participating Preferred Stock (1) 12/16/2005   C     624,630   (1)   (1) Common Stock 979,919 (1) 0 I By DJR US, LLC (3)
Convertible Series C Preferred Stock (4) 12/16/2005   C     270,587   (4)   (4) Common Stock 316,749 (4) 0 I By DJR US, LLC (3)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Blair John Allen
C/O DEALERTRACK HOLDINGS, INC.
1111 MARCUS AVENUE, SUITE M04
LAKE SUCCESS, NY 11042
      * Please see below  

Signatures

 /s/ Eric D. Jacobs as attorney-in-fact for John Allen Blair   12/20/2005
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Shares of Convertible Series A-1 Participating Preferred Stock were automatically converted into shares of common stock on a 1-to-1.5688 basis upon the closing of the Issuer's initial public offering on December 16, 2005.
(2) Excludes 58,936 shares of common stock held directly by Mr. Blair, as initially disclosed on Mr. Blair's Form 3.
(3) Douglas W. Aiken is a Manager and Member of, and John A. Blair and Raj Sundaram are Members of, DJR US, LLC (formerly known as Automotive Lease Guide (alg), LLC), and, as such, exercise voting and/or dispositive powers over the shares held by DJR US, LLC. Each of Messrs. Aiken, Blair and Sundaram disclaims beneficial ownership of all of the shares held by DJR US, LLC except to the extent of his pecuniary interest therein.
(4) Shares of Convertible Series C Preferred Stock were automatically converted into shares of common stock on a 1-to-1.1706 basis upon the closing of the Issuer's initial public offering on December 16, 2005.
 
Remarks:
* Mr. Blair is the President of DealerTrack Data Services, Inc.

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