i hate to guys but i beg to differ about being untracable. my dad has an 04. 5 and was able to try a buddies smarty for a day. after he reset it back to stock, had to take it in for an injector leak. (leak was prior to the smary) when he took it in they said there is a trip counter on the 04. 5s and up . soon as you put your stock software back it resets the timer. so when we took it to the dealer, truck said it ony had 3 hours run time on it and only driven for 84 miles. dealer said only way POSSIBLE to reset that timer is a programmer. not sure, we may be the only one thats had a problem as i have not heard of one other person with a problem taking it to a dealer.