This is a way off because I'm just building the basic layout now. I plan to use about half our basement and 0 gauage track. This week alone I picked up at least 100 10" sections of 0. I may have about 200 so far.
I also found an awesome way to rust Lionel track fast and make it look identical to the color or real track. If it weren't for that 3rd rail it would pass in photos as the real thing.
But back to the slot cars, I used to be into the big slots back in the 60's. We pretty much built our own cars. I may try to make my own cars for the train layout.
Question: What length would make an average car come close to matching 0 gauge scale? I was thinking like 3 1/2 to 4 inches???