19 CFR §115.68
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Any road vehicle whose essential features are changed shall no longer be covered by the design type approval. Such a road vehicle may be made available to a Certifying Authority for inspection and individual approval in accordance with subpart E of this part. However, repairs in kind do not constitute a change of the essential features.