Monrand Black Shift Knob Adapter,Gear Shifter Adapter Kit 14mm, Aluminum Alloy Universal Shifter Knob Adapter for Non-Threaded Manual Shifters M12x1.25 with 4 Adapter 8mm,10mm,11mm,12mm 465 ratings ...

That’s right, the knob that comes as factory equipment in that upgraded E46 that has a bit of a cult following. Mine is an aftermarket knockoff, but it had good reviews, so I bought it on eBay.