update: since posting the diffuser + Eis Race pics above, I replaced the Eis Race with a full Akrapovic exhaust. These are pics of the diffuser + Akra. Much better IMO.
2011 E93 M3 (JzB/FR-ext, M-DCT, Akrapovic Evolution exhaust, MS pulley, spacers, air filter, rear diffuser, a few other things...)
2008 E93 M3 (IB/G, 6MT, RPi exhaust, others... hit from behind and totaled); 2006 E46 M3C (CB/Cin, SMG, SuperSprint exhaust, others... retired); 2004 E46 M3C (CB/Cin, SMG, SuperSprint exhaust, others, spin out in rain and totaled); 2001 E46 M3C (SG/G, 6MT, retired)