For sale: Brand new TMS Power Pulley kit part # PPK-S65-L.
Sell for $350 shipped
Note: Please check the link above to make sure this is the correct part # for your M3! Turner says "Please select the year/transmission of your M3 (below) so that we may send you the proper parts for your application. There are specific kits for 2008 vs 2009+ model years, as well as manual transmission versus DCT sequential gearboxes."