Many thanks to all for the responses.

No leakage from the engine to the floor at all - I had any seals that were leaking changed out when I bought the car a few months ago. There's some oil leakage around the turbo - looks like a fine misting upward from the oil line. This is coupled with a hot oil smell after driving.

Some oil is being burned through the tailpipe, but only during moderate acceleration when the engine is cold. Hard acceleration when warm shows no smoke whatsoever.

PCV system has been checked and is clear. Will check turbo on cold engine via the time-honoured wiggle-with-finger method.

If the turbo is done, what do I replace it with? Which model of Garret turbo is it - T4? T5?

Thanks again for the reassurance and wisdom - I'm in uncharted feckin' water here. My last three cars were big North American lumps (two Caprices and a Crown Vic), and were dead-simple to work with and understand...

I'm also wondering if my Norwegian ancestry has anything to do with this. I know the Norski and the Swedes don't usually play well together. Perhaps this is some sort of cultural thing.