Good movie, I remember watching it as a kid. Richie's car in reality is an early Track T. The cars were stripped down Motel T roadster pick-ups (or Turtle decks), in most cases running sans pick-up beds and shortened frames. Many other modifications came along as they evolved.

Hot Rodding split into three distinct catagories; Street cars, oval racing and drag racing. Most believe it all started on the west coast. I am one that totally disagrees with that assessment. Vanderbilt, Astor, and many others where modifying and running their cars in time trials on Osmond Beach in 1904 or so, and on the street of Mineola/Jericho in 1907.

California gets a lot of credit for being the automotive hot bed for one reason, and one reason only, coverage. Hot Rod magazine came out and made California the Mecca of the car culture. The weather didn't hurt any either.
At that time, there were as many customs, hot rods and oval track cars in Kansas as there were per capita in California. You just didn't hear about it.

Sorry, I got carried away.