herrod exhausts are coverd under warrenty, as is some intake mods depends on who the maker is.. your mate might wana cheak that out, as for the tune, i doubt the workshop would notice it... the xr6T fails due to the factory actuators getting a hole in the diaphram causing them to overboost and shatter shit, any car is gona bend rods if it runs more then double the factory boost on a factory tune with such a large turbocharger... they blow out spark and eventualy blow out rods/pistons with the sorta boost they run.