Ive had my GMMG cat-back for a few months now and I had gotten used to the interior drone. I took it to my local garage to diagnose my frequent dead optima battery (alternator) and he informed me that the reason for the drone was that the i-pipe from GMMG was a bit short (also causing my leak that he welded to fix) and therefore my tip were about 6-7 inches from my bumper.
He is telling me that this is causing all that beautiful noise to bounce off the bumper and resonate into the cabin. His solution is to either weld in an extansion on each tailpipe then clamp the tips on OR get downpipes and ditch the tips. He suggested the downpipes because they would be cheaper and produce MUCH better sound.
I trust him and wanted to find out if anyone on here has downpipes and if so are they worth losing the visual appeal for the sound quality.