To beef up the Career mode, include Class E, P and X in the Open Class Tour. And also increase the amount of races to win each championship from 3 to 5 (edited😉)
I agree that it would be nice to include all the classes but 6 races each is too many.
It’s such a boring slog. Why on Earth would you want that? 8 laps of Lime Rock was quite enough. 
to bore me to death.