Speaking of custom exhausts, I've decided to take one for the team and be the first brave soul (that I'm aware of at least) to do a muffler delete on the N20.
After some standard ride-related mods, my F30 328i M-Sport drives like a dream (H&R Sports with BMS spacers 12mm front and 15mm rear, and Kumho Ecsta max performance non-RFT's on 18" Style 400M). I've also had a BMS Stage 1 for about a month and I've got all the power I need at the moment. My only remaining disappointment is the complete lack of exhaust note from the N20, and the fact that there's still a ways to go in the aftermarket before I can settle on which catback system I want to go with. After hearing the clips that are popping up of the PE system, I've noticed that the PE has a considerable amount of burbles and pops, and is pretty darn loud too. I'm convinced that there's not going to be a substantial difference from the PE to a straight muffler delete on the N20 so I'm gonna give it a shot.
I've ordered black 135i tips from Turner which apparently fit onto our stock pipes with little to no modification, and I plan on replacing just the muffler section of the stock exhaust. So this setup will be stock everything, which includes the cat, resonators, mid-pipes, etc., and also leaving the post-muffler exhaust flap/valve actuator in place. My thought is that leaving the flap/valve in conjunction with selecting Eco-Pro will provide a crude 'stealth-mode' option once the muffler is gone.
When the tips come in I'll take the car down to the local muffler shop and get some vids up shortly after everything is done. I'm thinking the work will probably take place over the weekend so stay tuned...