N.H. Rev. Stat. Ann. § 259:60-a

"Motor vehicle business" shall mean a business which is principally engaged in one or more of the following activities: buying, selling, or exchanging motor vehicles requiring registration for use upon a way, motor vehicle mechanical service, motor vehicle collision repair service, the reconditioning and restoration of motor vehicles, and the sale of motor vehicle parts. For the purposes of this definition, "principally engaged" means that the business derives at least 51 percent of its annual gross income from the motor vehicle business or, if there was no income in the prior year, 51 percent of the assets of the business are directly related to the motor vehicle business.