It's decently loud, removing the secondary, non o2 read cats will help make it louder. But you are comparing it to a Roush exhaust on a V6 Mustang, which is one of the louder Mustang exhausts. I had that on mine for a short time, as I hated the raspy tone, (and mines a 5.0) and switched it for Ford Racing set. Not sure how your girlfriend stands it on a V6, I've heard that exhaust on a few V6's, sounds awful.
