Hex Editing Crazy Taxi

[Washp]

I just got myself a mc2 racing wheel I was super stoked cause I kept hearing nothing but good things about its quality and feel. My main reason I got it was for crazy taxi, It just arrived today and I found out the gear shift is mapped to x and a. I am not able to remap the buttons in crazy taxi. I was wondering what would be a way I could mod the game to remap the buttons via hex editing or gameshark codes. Anyone have an idea of where I can start?