I love this vehicle controller.
I honestly can't even think of any real feedback. The driving feels right, and the drifting is fun. The only thing I can really think of suggesting, is to make the "drift" button act a bit more like a handbrake when there's no steering input, and maybe not let the car go in to reverse, if that makes any sense.
Anyway, keep up the good work, this fantastic, and has so much potential.