Hee hee Nigel, 'hold-ups' on a road! There have been many hold-ups here in Norfolk on our country pot-hole-ridden roads. I now imagine a gang of Norfolk peasants waving pistols and holding up beleaguered motorists! "Gimme yer bank card yew fewl, or oi'll shoot yew dead bor!"
Regarding 'thumbs up', I've always put up both thumbs when signalling approval, not just one. (I don't do things by halves!)