40 CFR § 1037.310
Audit procedures for trailers
June 9, 2020
(a) We may audit trailer manufacturers to ensure that trailers are being produced to conform with the certificate of conformity. If this involves aerodynamic measurements, we will specify how to adapt the protocol described in §1037.305 to appropriately evaluate trailer performance.
(b) We may require device manufacturers that obtain preliminary approval under §1037.211 to perform aerodynamic testing of production samples of approved devices to ensure that the devices conform to the approved configuration.