Sorry, I forgot to mention I'll be going with either the stock 265/40 PS2 18" or 275/xx (can`t recall which sidewall I have) 18 PS2, not the Cup tire spec listed below.
And thanks for the reminder!
(I'm going to hit the online calculators tonight and determine which is optimal)
'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.