These are the two pictures I found mounted. I was able to fit the challenge exhaust with 3.5" tips except for the spot on each side that caused the blemishes from heat. The 3M tape locations made good contact and never came off. The curve around the left exhaust outlet probably had about 1/8" more space between the bumper than the right but it wasn't noticeable. I thought it fit well for a replica but i don't have anything else to compare it to. I would have kept it on if I didn't change to the M-Performance exhaust which doesn't look good with a diffuser IMO.
2013 E92 M3 DCT/LMB/Blk Nov/Competition/Premium/Cold Weather/EPS/BMW Apps/SAT Radio/Corsa Exhaust