How about adding the Daytona 500 category? Since Daytona 500 is probably the most important race in NASCAR and Indy 500 category is already a thing, probably adding Daytona 500 would be a cool addition. Of course, it'd have similar rules as in Indy 500 (AI level higher than 70, 200 laps, starting from last, tyre wear 1, soft tyres, no boost), but instead of Formula Speedway cars there'd be stock cars.