A PAIR OF JUNKYARD CARS THAT YOU WOULD SEND RACING AT EACH OTHER FOR A HEAD ON COLLISION.ON IMPACT THEIR PARTS WOULD FLY OFF. a set of two demolition derby cars powered by 'T' grip rip cord that you pulled in the same way you'd pull start an old lawn mower,this rip cord had teeth that made the geared large centre power wheel spin. you and your friend ,at oposing ends of the room, would place the cars down and let them hurtle towards each other and upon contact the doors wheels ect would fly off in all different directions. after the dust had settled you'd simply snap the fallen peices back on and start all over again, GREAT FUN!! [Smash Up Derby By Kenner This crash set came with two cars that had one big wheel in the center. They came with a big gear like rope with a handle. Cars hit each other and parts flew off (like doors hoods etc)really cool when I was a kid. Came out about 1974 or 1975 I'm not sure exactly I was born in 1976 and my brother already had this toy. Plastic cars with parts that looked banged and beat up. When you smashed them together, the pieces fell off. "Crash, Bang, Smash 'em Up - Smash Up Derby is Fun!" Two plastic cars with a rip-cord to set them off go head to head "chicken" style, when the hit, the panels fly everywhere. You then simply click them back together and go again.