Section 541.4 - Definitions(a)Statutory terms. All terms defined in 49 U.S.C. chapter 331 are used in accordance with their statutory meanings unless otherwise defined in paragraph (b) of this section.(b)Other definitions.(1)Interior surface means, with respect to a vehicle part, a surface that is not directly exposed to sun and precipitation.(2)Light-duty truck (LDT) means a motor vehicle, with motive power, except a trailer, designed primarily for the transportation of property or special purpose equipment, that is rated at 6,000 pounds gross vehicle weight or less.(3)Line means a name which a manufacturer applies to a group of motor vehicles of the same make which have the same body or chassis, or otherwise are similar in construction or design. A "line" may, for example, include 2-door, 4-door, station wagon, and hatchback vehicles of the same make.(4)1990/91 median theft rate means 3.5826 thefts per thousand vehicles produced.(5)Multipurpose passenger vehicle (MPV) means a passenger motor vehicle which is constructed either on a truck chassis or with special features for occasional off-road operation and which is rated at 6,000 pounds gross vehicle weight or less.(6)Passenger car is used as defined in § 571.3 of this chapter.(7)VIN means the vehicle identification number required by part 565 of this chapter.59 FR 64168, Dec. 13, 1994, as amended at 61 FR 29033, June 7, 1996