These links listed below are great sites for cheats. im very sure you will find the cheat u need with thesse sites
Game sages
Best Cheats
Cheatcc
Gamesdomain
note: if u are looking for the midtown madness 2 all cars cheat your out of luck. THEY DO NO WORK. the only way to get them is if u do it the old fashioned way or u can download a saved game file with all the cars saved to it. to use this u have to extract(unzip) all files to the players directory and then enjoy all the cars! if u want this click here