Bring back that cars of the mid 70's, steel brakes, V12s, Little fronts, big rears, and make these guys drive instead of whine. This is NASCAR with no weight and lots of downforce, just the same car. Take away the aero packages too. What the car doesn't stick? Too Freaking bad. Its a corner, slow down for it. No traction control, I want to see some rubber laid down.
Take all that drive by wire crap away, enertia weights from a 2CV(!) Kers (if you want a hybrid drive a prius), and make the driver drive what he has. Change springs, shocks and gears and thats all you could do. These guys don't know what driving is.
And figure out how we can make em run Nuremberg Ring.