Very neat! Unfortunately it won't work with my remote shift or I'd be doing it myself
With the remote shift, you wouldn't have to cut the hole out would you? Just simply mount it to the floor? Then you get to use both the tray and the cup holder!
Surely if you use the metal retaining ring underneath it would be enough to hold it. It's a shame there's not a two holder version.
I'll try flipping it today and let you know!