i use the analog sticks for driving, the left for steering and the right for a acceleration and braking. perfect for controlling drift. also allows to play with out ASM or TC and still have good control of the car's direction.
I use the good 'ole defaults, too! I am left-handed as well, but I don't normally change buttons unless something just seems wrong. I can't even use the analog stick to steer.... I guess I am an old Nintendo four-directional pad believer!! LOL