Like I said, most of the cars that were really rotted, were just left to keep on going in the "old days". Or turned into tractors. And even then, there were enough model-As, Ts, and Bs to keep everyone occupied, so you wouldn't be driving around in a Diamond-T with the floor rotted out, or anything similair.
You wanted a cheap, good looking hot rod. Not something that broke tradition too much or looked like a pile of junk.