I know people have repacked the cars.ca2 archive without modifying files and got it to run... I want to know which software or methods they used to do it. cabextract extracts them so what can re create them hwnd what do u know about these files? i want to add cars to forza

i need to know what i need to know to be able to do it?!? please help!?!
Packing is easy, making cars it's a bit more timeconsuming. If you are making cars, can you please add teh truck in Terminator 3? If you do that, I'll repack teh ca2 for ya.