There's no evolution to the racing genre, other than realism, which is lost on most people. Otherwise it's exactly the same games we've played for a decade with tarted up visuals, whereas every other genre is undergoing advances (or did with the case of FPS/TPSes, which have now exhausted their progression and are becoming very samey).
I think it's a dying genre, like classic platforming (Sonic and Mario), and scrolling shooters that had their hey-day in the 16 bit era, and which will come back after a prolonged absence when gamers want a change from the current fashions.
Even FPS could be argued to be advancing. For example mainly recently with the original MW taking a almost MMORPG style progression to the multiplayer. That vein will be explored and exploited for a long time. Another area of improvement is in destructible physics like we see in Crysis, Crysis 2 and Battlefield BC.