An extreme sexual gearhead
who finds some aspect of internal combustion or vehicles erotic.
People turned on by humping motorcycles, the shape of car bodies, the sound, smell or look of exhaust.
Look at that motosexual, reving and humping his dirtbike and turning around to look at the smoke!
Yeah, that motosexual, ever since he put a cam in his chevelle, he has been driving around with a woodie