The following is taken from the 'FOJ Community Mod.txt' included in the FOJ FO2 mod archive;
How to use it:
The patch file provided is setup to run the mod right away. If the 4 FOJsmod.bfs files are found in game folder then all of its contents will load up with no issues.
1.Start up your game
2.Select (or create) a brand new profile that has not been used before. It is best to use a profile from 2-8 for the modded game, and save 1 for stock game. (delete a profile if needed to use for mod)
3.Goto the extras menu/enter codes screen and type in the "GIEVEPIX" code to unlock all cars and give one million dollars. (if you do not do this , you will be missing some cars)
4.Start a single player race to ensure all cars from carpack1 show up, if not re-enter code again. (sometimes if still not working, purchase a normal fo2 car in career mode, then try code again)
5.You may want to exit the game thru the game's exit button to ensure profile gets saved properly.
6.You should be good to go , we hope you enjoy the mod ;-p
There is some trouble-shooting information in the same text file, and the mod archive provides other text files/documentation
that are essential to read/know if you wish to edit/mod parts of the game itself.