You could always do that - at least according to the old anecdote:
Friday night at the pub, the plod is outside waiting. As it starts getting late, the first guy bumbles out looking for his car - he's stumbling all over the place, tries the wrong car repeatedly etc.: obviously drunk as hell. The plod is following him closely ready to bust him when he leaves - as others start getting into their cars and drive away. The bloke eventually finds his car (the only one left by then), climbs in and rolls out - to be immediately waved down, of course; except incredibly, he seems strangely sober now, and his alcohol level measures zero. "How is this possible?!?" the cop cries out "let's test again!". "Oh, it's quite simple" the man replies "it's just that I was the one on duty for tonight..."