You might want to try Refine, by Tunerworks. They did my 3m and there was lots of high end cars in the shop that day. Rob at Tunerworks recommends them, I will get them to do my car next year.
2011 E92 M3 | JEREZ BLACK | EXTENDED BAMBOO NOVILLO | EXECUTIVE PKG | M-DRIVE | EDC | M-DCT
MODS | KW S/O | HRE P40SC | Akra Evo |ESS Akra Tune | BMC drop in | StopTech Trophies | TMS Pulley | LUX V3