(e) "motor vehicle" means a motor vehicle as defined in clause (18) of section 2 of the Motor Vehicles Act, 1939 and includes motor cars, motor taxi cabs, motor cycle, motor cycle combinations, motor scooters, motorettes, motor omnibuses, motor minibuses, motor vans, motor lorries, trailers and chassis of motor vehicles and bodies or tankers built or meant for mounting on chassis of motor vehicles, but excludes tractors