What you do is buy a VW jetta vr6 or whatever it is, then go to buy modifacations. Go to the engine section, buy everthing at every level( example: buy all of the exhuast upgrades. and the same with everything else) and i mean everything both turbo and supercharger. Then buy the new engine. So the glitch is if you buy everthing on the stock motor, then buy the new motor. You go back and equip the stock motor after buying the new motor then you can sell the new motor for i think 42000.00. And you can keep doing this over and over untill you want to stop. Unlimited money possiblities. All you do is keep buying the new motor which should only cost 2500 if you do it rite in the first place. then you equip the stock motor and rinse and repeat. Sorry i had this long thing when i could have probably simplified it a little.