49 C.F.R. § 523.4 Passenger automobile.
Title 49 - Transportation
A passenger automobile is any automobile (other than an automobile capable of off-highway operation) manufactured primarily for use in the transportation of not more than 10 individuals. (Sec. 301, Pub. L. 94–163, 80 Stat. 901 (15 U.S.C. 2001)) [42 FR 38362, July 28, 1977]
Title 49: Transportation
PART 523—VEHICLE CLASSIFICATION
§ 523.4 Passenger automobile.