I have the Roush splitters and the BOSS side exhaust, running them wide open and no issues on melting. I was already running the Flowmaster Outlaws, so I was already pretty loud. Sound now, I would say pretty much the same on the outside, a little deeper note now. Inside, I actually hear the exhaust less. Back to too loud as in annoying neighbors, well, haven't left my house real early yet so don't know about that, but no one has said anything to me about the car being too loud.
2013 GT 6 spd, GT500 mufflers, BOSS quad exhaust, Roush CAI, Barton shifter & 2 post bracket
CS GT-40 Wheels, Hotchkis sway bars, upper and lower control arms, springs (1.1/1.6 drop) and adj panhard bar KONI yellow struts and shocks J&M caster/camber plates,
BMR Upper control arm mount and lower control arm brackets.