Dinan is a joke and I use to be a fan.
Their "warranty" is what people refer to to justify the high price but it is a load of crap.
I bought one of their exhausts a couple years ago. The fit/finish was horrible. One set of tips was longer than the other. I proved it to Dinan with pics and measurements. They agreed and then said it was within their manufacturing tolerances. It didn't fit either. I had to go to a custom exhaust shop to have the hangers bent, etc. to get everything to line up.
So much for their vaunted warranty. Buyers of any Dinan products beware ...
2013 E92 M3 with ESS VT2-585 SC, StopTech BBK, M Perf Exhaust, and a bunch of carbon fiber ...