My experience installing my 4in. Wiles in my ‘15 M6. I had to pull it out two or three times to fit it but we’re all good. Got it up to about 95 but no vibrations. You could see on the d/s weld exactly where it was hitting the shifter and it left a mark on the shifter as well. I just hit those areas (on the shifter, didn’t touch the ds) with a grinding wheel for a while. Took off enough material to clear it, and when I took the driveshaft out for the last time in order to put Loctite on the bolts I hit it one more time just for a little extra insurance. Only problem I couldn’t properly torque them down as I couldn’t get a torque wrench in so I just tightened them up nice and firm. 👍. Not a tough job at all, just a little tedious but if you guys don’t have an issue with interference between the Barton and the d/s, it’s a bunt. R&R the exhaust is cumbersome with one person but dooable. Two people would be a big help. A worth while mod. Don't forget the cdv removal as well. Good luck.