Back in my youth, I used to work with my uncle as an upholsterer. I used to take the seats apart, he would sew them, then I would put them back together.
Anyway, at one used car lot, I saw a guy turning regular car tires into white walls. He had a machine he would use to do it. He would jack one of the tires off the ground, put the machine on it which would spin the tire, then he would cut a shallow groove into the side wall of the tire. Kind of like using a lathe. After the groove was cut, he would then paint the groove white. Kind of neat to watch when you're 15.
You should have seen the rusty '79 Firebird they turned into a fancy Trans Am in about 10 hours...fresh paint, decals, and all. We installed the carpets in that one while they were filling it up with bondo.