Have the C5 Carbon Fiber on my 06 ST. They run cooler and have an artistic flair above the Titaniums. They sound fantastic but if they are too loud for your taste, I suggest ordering the P1R Power Tip with it. They are gold, an easy install,complement the gold band of the canister, and you'll get a mellower tone. Since you'll be running leaner with the sytem, you might want to consider changing your fuel pressure regulator (FPR) available from Tom at Turbocity. I went from a stock 50 psi FPR to a 62 psi FPR with the Two Brothers and a K&N filter...and it made a very noticeable difference.:clap2: