[terry251]

reddeth, here is the definition for motor vehicle as it pertains to the CO emission testing program (see CO State Statutes 42-4-304(18)(c). The applicable definition is bolded.

"Motor vehicle", as applicable to the AIR program, includes only a motor vehicle that is operated with four wheels or more on the ground, self-propelled by a spark-ignited engine burning gasoline, gasoline blends, gaseous fuel, blends of liquid gasoline and gaseous fuels, alcohol, alcohol blends, or other similar fuels, having a personal property classification of A, B, or C pursuant to section 42-3-106, and for which registration in this state is required for operation on the public roads and highways or which motor vehicle is owned or operated or both by a nonresident who meets the requirements set forth in section 42-4-310 (1) (c). "Motor vehicle" does not include kit vehicles; vehicles registered pursuant to section 42-3-219, 42-3-305 (4), or 42-3-306 (4); vehicles registered pursuant to section 42-12-102 that are of model year 1959 or earlier or that have two-stroke cycle engines manufactured prior to 1980; or vehicles registered as street rods pursuant to section 42-3-201.

Good Luck,
Terry