+1 on the turbo back exhaust and boost controller... mitsus respond good to turning up the boost and freeing up the exhaust... as for the warranty, mitsubishi throws it out the window the minute you put ANYTHING aftermarket on your car (wheels too, if i'm not mistaken) i went to the dealership before I was deployed and they were really adamant about putting anything on the vehicle. i was planning on getting an evo RS when i got back from deployment cuz all my cars have been mitsubishi (3000gt turbo SL and 1g eclipse GSX), but i guess i wanted to just change over to something different, thus, thre reason for the 180sx... (besides, i don't have enough friends to put into a four door anyway , haha)