This isn't the first time reading about the subframe issue on a car that had an aftermarket exhaust. Perhaps it isn't bad installation, but very particular bolts in respect to torque- or perhaps the bolts have issues if they are EVER removed. Sounds like I'll spend a couple more bucks and have exhaust installed for $200 at the dealer.
BTW, have you watched the M exhaust video? Full on burn outs. Redline shifts. The car can handle it, no problem. If you've messed with the subframe bolts and incorrectly torqued them and there is breakage, no one to blame but your installer.
E92 M3 MR on Red/Black ZCP Sound
2007 997S - sold
2003 E46 M3 Steel Grey on Red- sold
1997 E36 M3 Arctic Silver on Black- sold