If it ran like ass on your PC, I'd expect the control to be lousy no matter how well it might be implemented, but seriously -- WTF are you playing a driving game with a keyboard for in the first place?
You really can't fault a driving game like this for having poor keyboard control in this day and age.
You my friend, have just stepped so far out of the box that a hobo moved into it!
There's plenty of games that run like ass but still have responsive input. Besides, it doesn't seem to be related to the performance of the game, it's a general problem and people seem to be fixing it themselves by modifying files.
And what the FUCK is wrong with playing a racing game with a keyboard? It's just like a d-pad and plenty of people play it that way. Also what the hell is "this day and age" supposed to mean?
You're an idiot, that's what.