Buy American Improvement Act of 2007 - Amends the Buy American Act to: (1) prohibit federal agencies from determining that it would not be in the public interest to enter into a contract subject to Buy American requirements after a solicitation of offers notice for such contract is published; and (2) apply Buy American requirements without regard to whether products to be acquired are for use outside the United States if they are not needed on an urgent basis or if they are acquired on a regular basis. Requires before a contract is entered in the latter type of case an analysis of the difference in costs of such products from manufacturers inside and outside the United States.
Requires federal agencies to: (1) give preference in the procurement process to a company that manufactures the solicited product in the United States, if such company's bid is substantially the same as a bid made by a non-U.S. manufacturer, or such company is the only one that manufactures the product in the United States; and (2) report for FY2007-FY2011 to specified congressional committees on the amount of agency acquisitions from entities that manufacture products outside the United States (excepts intelligence agencies).
Prohibits an agency head from determining that articles to be procured are not available from domestic sources without first determining that domestic production cannot be initiated to meet procurement needs, and that a comparable product is not available from a company in the United States.
Defines a product as made "substantially all" from domestic components when the cost of the product's domestic components exceeds 75% of the cost of all the product's components.
Requires the Comptroller General to report to Congress with recommendations for determining whether an acquisition would involve unreasonable cost and be inconsistent with the public interest for purposes of applying waivers of Buy American requirements.