GTA – iPhone

Rockstar Games just released Grand Theft Auto: Chinatown Wars for the iPhone and I started playing it last night. It’s fun, but I don’t see myself becoming addicted to it the way I did with GTA 3, Vice City and San Andreas.
A big issue I have is with the driving controls. To steer you have a left and a right button:
Why not have one continuous button with gradation from left to right?
I’ve comped up a revised version I think would work better: