19 C.F.R. § 115.64 – Plan review.

(a) A manufacturer or owner who wants road vehicles to be approved by design type must submit the plans and specifications of the road vehicles to the Certifying Authority.
(b) The Certifying Authority that examines the plans and specifications submitted in accordance with paragraph (a) of this section shall:
1. (1) Approve the plans and specifications in accordance with the requirements of § 115.65 and arrange to inspect a road vehicle in accordance with § 115.66; or
2. (2) Advise the applicant of any necessary changes to be made for compliance with the requirements of § 115.65.
(c) If changes in design of the road vehicle are made during production but after approval of the plans and specifications by the Certifying Authority, the manufacturer shall immediately notify the Certifying Authority and furnish it with “as-built” drawings of the road vehicle so that the plans can be reviewed and one or more road vehicles inspected during the production stage to confirm that they continue to comply with the requirements of § 115.65.