I figured out a cheat in forza that makes you 45k each time you do it! Its a glitch in the game. Buy a vw jetta gls, the 20k dollar one. Then do every motor upgrade, buy all the cheap ones up to the most expensive ones. Then swap the motor. Reinstall the stock motor and sell the moded one for 45k. Then rebuy the mod motor for 2500 reinstall it, then reinstall the stock motor and resell the modded motor for 45k. Its works perfectly. my stable of cars has grown significantly now! My 959 runs a 9.366 pretty consistently now!