I used the Dutch Super7. Looks good.
I’m waiting 48 hours before I put it under stress. 36h so far
(I’m confident in will be ok over the winter. The question is what’ll happen in our summer heat).
If one has able hands it’s definitely worth the effort. IMO puts the interior in a different league. This is a super option if you don’t want a z3 cup holder. If you have one, there is much simpler solution. Just buy a replacement e46 top armrest (a few bob on aliexpress), remove the two ears and silicone a plastic hinge to the back of the cup holder.