even if you do say get a exhaust,mbc,intake,and say a flash or custom tune this could all be removed in about 2 hours. And to flash your car back to stock just get yourself a laptop and a tactrix cable download ecuflash. Then all you have to do is save your stock tune and your custom tune on your computer and flash it back to stock before you go to the dealership. But i dont know if a dealership would go that far to look into your ecu only if you blew the motor or something like that