Example 1: Motor vehicle bodies or bodies on vehicles used in combination with exempt vehicles, such as trailers or semitrailers, permanently mounted so that they effectuate the purpose for which the vehicle is intended are exempt from tax.
Example 2: Devices used in or on vehicles for effectuating business purposes, such as shortwave receiving and transmitting of messages, are not considered an integral part of such vehicle and are not exempt from tax.
N.J. Admin. Code § 18:24-7.18