Slight thread hijack, sorry, but my daughter has just bought a 2013 90. It has only done 29000 miles, and looks generally very good. Is there anything else apart from the useful stuff above I should look out for? I am used to 300tdis.
I'd pull the lead from the start solenoid and spin it over and get oil pressure for a few seconds before starting Then let idle for a few minutes before anything more strenuous. Handbrake might be stuck on
I have I think the same clutch as @TSDin a 300 with VNT, and it is a bit rattly but so far has been reliable including trailer towing and manouevring, over about 5 years. I think it is AP basically but built to M&D spec. Its Valeo predecessor catastrophically lost the springs in the middle. (Ie the middle of the clutch plate and also the middle of Chorley.)
I have just had a fuel pump rebuilt, and that had quite an effect on noise, as well as on power. Timing is also a factor, advancing to get best power will increase noise. You pays your money ...
There is a series of Brittanica Restorations videos on stripping and rebuilding the steering box, generally without special tools. He does use a spring balance.