(C) Publication of proposed regulations Proposed regulations to implement this section shall be published in the Federal Register by the Secretary not later than 18 months after such date of enactment. (D) Committee A negotiated rulemaking committee established pursuant to section 565 of title 5 to carry out this paragraph shall have a maximum of 11 members limited to representatives of the Department of Transportation, urban and rural recipients (including State government recipients), and transit vehicle manufacturers. (E) Extension of deadlines A deadline set forth in subparagraph (C) may be extended up to 180 days if the negotiated rulemaking committee referred to in subparagraph (D) concludes that the committee cannot meet the deadline and the Secretary so notifies the Committee on Transportation and Infrastructure of the House of Representatives and the Committee on Banking, Housing, and Urban Affairs of the Senate. (3) Savings clause Nothing in this section shall be construed to provide additional authority for the Secretary to restrict what a bus manufacturer offers to sell to a public transportation agency. . 2303. Bus testing facility Section 5318 of title 49, United States Code, is amended by adding at the end the following: (f) Testing schedule The Secretary shall— (1) determine eligibility of a bus manufacturer’s request for testing within 10 business days