[isugoo]

There is not much options since:
a. most of aftermarket knobs don't light up (lightup 6 speed is still cool things in M cars).
b. most of owners don't want to cut their shift boot.

You can find it from AA. I heard that it feels good when you shift but looks like an ass with a chopped boot.

May think about something else. M t-shirts, key ring etc of stuff from the dealership if your buddy already have typical inexpensive mods (like painted kidney grills, fender grills, painted reflector).

OR matching color highly detalied 1:18 diecast from BMW.