Really? I thought they had to prove intent to drive which basically means keys in the ignition. I regularly get dropped off at home after a gig where I may have consumed alcohol and open up my car to put my amplifier in the back. If I was charged based on this I would definitely argue that there was no intent to drive.
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.