I guess this one turned up in European Car first. I learned about it from Audifans. The 1997 Passat cupholder is made to attach with two bolts - you just drill the holes and it has its own built in nuts. Stability limit is a hard left accelerating turn with a medium Dunkin Donuts coffee - good thing those lids stay on!
It is VW part number 3A1 862 531 01C and I paid $37 for mine. I hear they can be had for less.
A wonderful addition, makes my Audi feel more like a minivan.