Alright I'll weigh in.
Design looks good, though it would be nice if they would set the muffler straight back to the left hand exit, that should improve flow
Tips: DEFINITELY dual wall stainless.
Whatever it is it needs to be a bolt on solution, and hopefully an axle-back with optional mid-pipes. Dual in-Dual out would be nice but that means it would have to be a downpipe back solution, no? That will drive the price way up.
2010 135i M-Sport 6MT Jet Black