Down in Louisiana... 03 no cladding with 130 thousand miles here. I had a cat converter go bad and had a Flowmaster Big Block muffler installed then HPTec III tuned to 87 octane so far...I couldnt believe the difference. Added a Volant CAI and really couldnt tell much if that helped. The only thing is the roar if you pulling something from the Volant...dont like that. The exahust muffler was less than $200 installed which is cheaper than a Cat-back system and you still retain your stailess pipes! Hyper Tec III I got off of Ebay for a $150. This is definitly a way to go and feel the change in the seat of your pants!