Without the Bottle Opener there's no effective cup holder 
WITH the bottle opener there's still no effective cup holder either

I've used mine when camping at Inters and other shows. I was on my way to Inters this year and had a sinking feeling in my stomach when I realised I'd not packed one.....then remembered that there's always one in the car!

I bought my car new and it was the first thing I checked when the car got handed over to me!
The Mk 4 cupholders that popped out of the dash were better though. I find the Mk 5 cupholders don't hold anything bigger than a 330ml can without it toppling over

(I usually buy a 500ml bottle).