These guys have some wide bodies in stock car style.
I'd e-mail them and tell them that you have a RC10L 235mm wide car and are looking for a stock car body.
Parts are actually fairly easy to come by
front end is the compatible with the associated RC12L3 and RC12L4 tons of parts readily available. Be aware the 12R5 and 10R5 front ends are not compatible.
Irrgang racing service has lots of parts. Again e-mail Dave Irrgang, I hear from the people I race with he's top notch. Never met him but his service when I have ordered from him was super.
Doug Powell still offers a carbon fiber chassi and pod replacement called Max10. It's not on his website but if you e-mail him he'll help you out. Again I've never met him but his reputation is excellent.
Cheapbatterypacks.com can make you sub c saddle packs, but you'll have to Dremel out the slots on the chassi to make them longer.
Best of luck