Jim,
At this time it is not against the law to own an unregistered car in this state if you just use it on a track. They did try that many years ago and all of the guys that have race cars said ok, fine, if we have to register them then we drive them on the street. A couple of lawsuites got rid of that insane idea. So if you use it just for off road use on a track or if you have enough land to make your own track, they can't do anything about it. YET !!!
Ron