The E46 330 and Z4M both list a GS6-37BZ transmission, but the part numbers are different.
The 330 lists part #23007532498, and the Z lists #23007837983. Both list for $3801.30 + core on realoem!
In any case beta confirmed we should be able to have someone with an E46 (ZHP maybe) help VibraTechnic fit the brace. The mount itself seems to be shared too, and it fits on
a ton of other cars as well.