I have one of the stainless Ultimate cupholders in mine. I like it very much.
It just slips in place with the tang sliding up under the bottom edge of the console. And holds drinks quite well. I only have one on the passenger side of the console.
BMW Cup Holders, Porsche Cup Holders, Ultimate Cup Holder - Cupholders / Drink Holders for BMW 3 5 7 Series, Boxster 911 Z4 Mercedes Audi NSX other fine cars.