No muffs ain't bad, as long as you watch your surroundings and don't push the gas when you see a cop you'll be fine. You still have a cat and a res so that will kill some of the noise.

Try driving a GTP w/ open TOG headers 15 miles! Boy that was loud! I used back roads all the way to the exhaust shop (it was the closest shop who wouldn't ***** about not having or wanting a Cat installed) and of course I passed a Hi-Po on the way. I let off the gas as soon as I passed him (about 45 mph) his brake lights were on and watched me till I went over the hill. I didn't press my gas until I was up over the hill and a little ways away, I probably crested the hill at around 25mph before finally going downhill. I know if I would of tapped the gas he would of came after me...