https://en.m.wikipedia.org/wiki/NASCAR_Convertible_Division
For four years in the 1950s, NASCAR had a convertible division. 20 of them ran in the '59 Daytona 500.
https://en.m.wikipedia.org/wiki/NASCAR_Convertible_Division
For four years in the 1950s, NASCAR had a convertible division. 20 of them ran in the '59 Daytona 500.