I take my m3 too Mike&Henry's in western springs for regular service they're good, he's been there forever. For performance go to Chicago performance and tuning. Talk to Al at CPT. He's the best hands down, he's not the cheapest but he doesn't do anything half assed. He's done both of my S4's and m3.
Last edited by Ntrb8s4; 01-26-2013 at 08:58 AM.