They used to do this in BTCC back in the 80's, classes A,B,C,D, sierra cosworths right down to Toyota corollas. Basically each car won its class so there where 4 winners in each race, if a class D car kept on getting good results but NOT actually winning a race while a class A car had a few DNF's then it would be possible for a class D car to win the overall championship
The championship was run with a mix of classes, divided according to engine capacity, racing simultaneously. This often meant that a driver who chose the right class could win the overall championship without any chance of overall race wins, for example, in the 1980s Chris Hodgetts won two overall titles in a small Toyota Corolla at a time when most of the race wins were going to much larger cars; and while the Ford Sierra Cosworth RS500s were playing at the front of the field, Frank Sytner took a title in a Class B BMW M3 and John Cleland's first title was won in a small Class C Vauxhall Astra.