You can find .pdf files of the rulebook at the following address:
http://www.modelaircraft.org/templates/ama/compreg.asp

The section you are looking for is the RC Aerobatics section. Download this section and go past the RC pattern rules. The rules regarding legal aircraft are 3.1 and 5.3 + 4 of the Scale Aerobatics section. Basically, these get rid of the 10% rule and say the plane just has to be recognizable as a plane that is a replica of a plane capable of flying the sequence within the box. It's very open to interpretation!

If you have to have the 2 piece wing, the Great Planes Extra ARF has that. I think what you are going to find, however, that not only is a one piece wing going to be heck to get in your corolla, but the fuse will be as well.

Good luck with your flying.
Don't forget to have fun!!

Gary Hunt
Rantoul, Il