I can tell you right now I would never buy a car with any aftermarket parts on it unless I personanly knew the driver. A car with performance parts has most likley been run pretty hard, why else would they be on there. From a finacial standpoint you could dump another 2500$ in performance parts into it and it still would'nt be worth anymore. If you want to sell it, sell it stock if you still have your old parts and sell the performance stuff, you will never get as much out of a car as you put into it.