49 CFR § 567.7 - Requirements for persons who alter certified vehicles.
(a) With respect to the vehicle alterations it performs, an alterer:
(1) Has a duty to determine continued conformity of the altered vehicle with applicable Federal motor vehicle safety, Bumper, and Theft Prevention standards, and
(2) Assumes legal responsibility for all duties and liabilities for certification under the Vehicle Safety Act.
(b) The vehicle manufacturer's certification label and any information labels shall remain affixed to the vehicle and the alterer shall affix to the vehicle an additional label in the manner and location specified in § 567.4, in a manner that does not obscure any previously applied labels, and containing the following information:
(1) The statement: “This vehicle was altered by (individual or corporate name) in (month and year in which alterations were completed) and as altered it conforms to all applicable Federal Motor Vehicle Safety, Bumper and Theft Prevention Standards affected by the alteration and in effect in (month, year).” The second date shall be no earlier than the date of manufacture of the certified vehicle (as specified on the certification label), and no later than the date alterations were completed.
(2) If the gross vehicle weight rating or any of the gross axle weight ratings of the vehicle as altered are different from those shown on the original certification label, the modified values shall be provided in the form specified in § 567.4(g)(3) and (4).
(3) If the vehicle as altered has a different type classification from that shown on the original certification label, the type as modified shall be provided.