49 CFR §576.5

1. (a)Each manufacturer of motor vehicles, child restraint systems, and tires shall retain, as specified in § 576.7 of this part, all records described in § 576.6 of this part for a period of 10 calendar years from the date on which they were generated or acquired by the manufacturer.
2. (b)Each manufacturer of motor vehicles and motor vehicle equipment shall retain, as specified in § 576.7 of this part, all the underlying records on which the information reported under part 579 of this chapter is based, for a period of five calendar years from the date on which they were generated or acquired by the manufacturer, except as provided in paragraph (c) of this section.
3. (c)Manufacturers need not retain copies of documents transmitted to NHTSA pursuant to parts 573, 577, and 579 of this chapter.