My cup holder extends from my ulna to the end of my phalanges. Actually I have two (four if I have my passenger seat filled). They are pretty versatile...they assist with starting, shifting, steering, and all number of other activities when I'm driving.
They also go with me when ever I park my VS so I always have a helping hand (see what I did there?).
All kidding aside: those are quite nicely done and I can definitely see the benefit! I can't think of much that would upset me more than a spilled beverage rolling around unrestrained at my feet.