A Friend of mine who owns a Garriage sent me this..
"there is a batch of Audi 1.8 5 valve turbo engines with a problem with the cambelt tensioner, apparently they seize causing the belt to jump off its tensioner causing the pistons to hit the valves. mega expensive".
Has anyone else come across this or know anything about it. He had to do the mod for an A6 recently with the same engine.