Ok - like a good boy I have read the FAQs and done a search but none seem to describe what I experienced this morning.
Drove off from cold and it was clear I was driving a normally aspirated 1.8. No drama, no fuss, no turbo.
Got to where I was going about 5 miles away and left the car for 5 minutes - got back in and hey presto; plenty of turbo.
From reading the aforementioned FAQs and search results this could be due to a number of things but nowhere did I read that it comes and goes like it did with me.
Anyone got any ideas or is it a trip to my local Mr Audi to plug in his vag...?