Had my local muffler shop install the magnaflow mufflers (part # 14816.) I wanted to experiment with this before I dumped more money on getting a high quality, crafted by God exhaust--and suffice to say, these $250 mufflers (total) sound pretty damn wicked and throaty for the price. There is some drone around the 2500-3200 rpm range if I lug the engine, but if I leave it in cruise control at 65 mph, its tolerable, with some "humming" from the rear. I am thinking a new X-Pipe (the stock m3 x pipe, from what I have read, is a poor creation of what a true crossover is supposed to be) will remedy this some more. Maybe I will see if a new set of connecting pipes without the oem hydroformed pipes would help, too. I can get the magnaflow tru-x crossover for 60 bucks through a friend and can get it installed for free. I may do this to see if it eliminates the drone a bit more. I also don't have the secondary cats in my car either.
Overall, I paid $250 shipped for both mufflers, and paid $100 to get them installed. $350 total investment. Muffler shop cut off the stock muffler and welded in the new mufflers in the locations where the connecting pipes met with the OEM muffler. Fitment is great, and it looks more aggressive if you look at it from the rear (the finned differential is awesome.)
I will follow up once I have driven some more miles on it and perhaps it will mellow out some more, and will install the new x pipe on it, as well.
I have attached some pictures, and I made a quick video that I posted the link to underneath the pictures. I only revved to about 5000 rpms due to my next door neighbors having a labor day party and didn't want them to be angry.
2008 (07/08) E92 M3 BPM Stage II Tuned by Mike Benvo, 6MT, Turner Test Pipes, Magnaflow Custom Catback Exhaust (Magnaflow X Pipe, secondary cat delete, Aero Resonators and Helmholtz Chambers),Vorsteiner CF Lip, Hamann Style CF rear diffuser, CF Rear Decklid Spoiler, BMW Performance Kidney Grills, CF Side Grills, OEM GTS Wheels, K&N Drop-In Filter, GP Thunder 8k Angel Eyes, Painted Reflectors.