BIMMERtips - The single button featured on the BMW E46 M3 CSL steering wheel was the DSC M Track Mode button. This did not fully turn off DSC but significantly lowered computer
BMW E46 Racing wheel – KMP Drivetrain Solutions
01-06 BMW E46 325 328 330 M3 Steering Wheel Lower Trim Carbon Fiber | eBay
E46 M3 Steering Wheel - For Sale - bimmersport.co.nz
BMW E46 M3 01-06 OHC Carbon fiber Steering Wheel Tri Stitched Manual L | M Parts Worldwide LLC