I have two fx 50s. I put the Borla cat back exhaust on them. Sounds Great! I now have a qx-80 for real estate. They sell the same Borla for my 80, but I'm afraid it might be a little loud for showing buyers. My local exhaust guy recommended a large magnaflow muffler, and if it's still too quiet take off the resonator. Has any one tried this (or any other) exhaust systems or modifications?