Quick update on this. Checked all hoses (intercooler & turbo) and cleaned EGR (not too sooty), but yesterday went to Flamingo Land for sons 3rd birthday and, after the wife dropped a gear to overtake a couple of tractors, there was a 'James Bond' type smoke screen out the back. The strange thing is the car was driving great with no smoke on the motorways etc., even at 'higher' speeds, and no smoke during the 'hoofing' but it started smoking AFTER we had slowed down to normal speeds (immediately when getting back 'onto throttle' after the overrun) and took a good few 1/4 mile to fully clear. The smoke was light grey/white so i'm fearing the worst now. Also noted that there is a slight oil leak at the manifold downpipe-to-system joint. I'm thinking turbo oil seals now but can these be replaced or is it a new unit? Whaddya think fellas?