I think the closest things the decepticons really had in the motor vehicle category(and loosely at that) were the constructicons who were construction equipment, and the triple-changing decepticons:Blitzwing(tank), Astrotrain(Train), and Octane(a fuel truck). Also the stunticons were little decepticons who turned into various vehicles to screw with the autobots on the roads. Yeah I had to look that stuff up, I'm a transformer nerd, but not that much of one. I'd definitely put the VX in with the decepticons though, and I will definitely agree with Bart about Cobra. It just seemed especially during the 80's that the bad guys always have the cooler gear, which puts the VX firmly on the side of the decepticons. Autobots sporting fangs and slightly menacing headlights just doesn't work for me.