Honestly, there are enough systems on the market that there is NO reason you should be getting a system that needs to be cutting the stock system.
'08 M3: AA G2L3, Catless X-Pipe & Sig Series Rear. AP rods. TC Kline EDC Coil Overs. MRF Alum Sub Frame Bushings. TMS Delrin Diff'l Bushings. BFI Motor Mounts. Recaro PP. BMW Perf Steering Wheel. P3 Gauge. PS Overflow Kit. APEX ARC-8 18"x9.5"/10.5". Conti Slicks 275/35F 305/30R. Stoptech Pads/SS Lines. Cantrell Brake Ducts.