I really wish they'd made it a hybrid system. Where there are levels like now for the rubbish drivers to be able to do races, BUT each licence counts as a specific level with regard to races.
So:
B=lvl5
A=lvl10
IC=lvl20
IB=lvl25
IA=lvl30
S=lvl40
Or something along those lines
So for example a race will say you need either lvl 21 OR IB licence. So now with the Endurance races, having the Special licence will let you do them, you wont BE lvl40 but can do those races. It would completely destroy the grind issue and at the same time still give the player that doesn't like the licences a chance.
Required levels for cars is just stupid though.