Yes there is, but it requires a lot more than bruteforce and a hex editor. Custom firmware and intimate knowledge of the PS3 language are a good start. Have a look into modifying ELF files, there's a thread floating around here about people starting to discuss doing this which i'm sure will become more common and openly talked about now that GT6 is imminent.

This is good news. I'm looking to get rid of the wing on my Taurus SHO, but you cannot add a custom wing to it in-game.

I uploaded the .ELF file in the modding section. I'm not familiar with PowerPC so I gave up on it. Didn't even stop to think about the possibility of taking the wings off of cars you shouldn't be able to. Now that I think of it though you should be able to change wheels like in the 1.00+ patches if you can figure out what to change. I may attempt it again but it's a lot