Just installed full cat-back with LXR GTC with wireless EV control on my F12 M6. Sound is freaking ridiculous. It makes u want to drive so much more aggressive because the sound to me is THAT much better than stock. Mustang dyno before and after same day showed 14hp increase at wheels (501hp). Not as much as advertised but I was going for sound. Valve works well to quiet down to near stock. I'll post more info and pics/video tomorrow over on M6 forum.
'13 F13 M6 - Dinan Stage 1, Meisterschaft GTC, Carbon Filter Delete
'14 Jeep SRT
'15 F82 M4, SO/SO - SOLD
'11 E92 335is, Dinan Stage 2 - SOLD