Currently (at least for Dualshock 4 support) the controller layout for Accelerate is really bad. Due to the shape of the controller it’ll cause your hand to cramp after a few rounds. Having acceleration / forward on “X” is not optimal.
I made a little diagram of what an optimal controller layout would look like for the DS4 (with two options for Drift and Powerup).
Binding Accelerate to R2 and Drift to either L2 or Circle will be more natural and cause less of the “claw” shape (and thus avoid causing cramps). Putting Accelerate onto R2 also opens the door for force-based speed (softer input causes slower driving) if that was possible.
Horn would also be more optimal on the L3 / Joystick Click, emulating its placement in the middle of steering wheels (and freeing L1 for Reverse, a more important control).