Perfect example is if you look up Subaru and pick to build a sti then it has options for catback exhaust shirt shifter and a few other things I think but you can order it brand new from factory with that stuff installed. If someone from the dealer tries to void a warranty then ask to speak to the general manager and piss an moan until you hear what you want. By law they have to document and prove the mod damaged the part and can then only void warranty in that part. Just saying.