Just look it up, the M Sport part number for the front sway bar is 31356766288, 26.5mm.
The M Sport rear is 33556764425, 14mm. Non-sport OEM is 13mm.
If anyone with a non-sport E9X, and give me your vechicle last 7 dig of your Vin number I could look it up at Realoem.com.
Last edited by Josephkao; 11-09-2011 at 05:27 PM.