Pinched hose between the inlet manifold and the boost pressure sensor.
Pistons/piston rings.
Excessive fuel consumption.
Loss of power above 3000rpm.
Disgraceful service from BMW and two of their dealers.
I used an independent engineer to assess the vehicle. Found excessive metal content and soot in the oil and excessive cylinder leakage. BMW still argued saying the car was within their specifications.
Ultimately took them to court where they settled prior to trial. Dealer bought the car back at market value and paid compensation for cost of the additional fuel used.
It seems that they don't want to fix your car unless it stops going and they can't get off the hook. The warranty gives great peace of mind until you need to use it.
I found the comment about the BMW defined specifications interesting.
I had owned a BMW K1100 LT Bike with 20K on the clock. It used 950ml oil per 1000 miles which I found to be excessive, my previous K100 used virtually no oil and oil changes were only carried out during service every 6000 miles.
When I took the bike back to the main dealer, he quoted the BMW spec. that states an oil consumption of 0-1000ml per 1000 miles. As my bike was only just within spec, the dealer gave me a litre of oil and indirectly told me to F... O..
A two stroke wouldn't use that much oil. If BMW allow such huge tolerances I don't rate their engineering skills. I would not touch a BMW car or bike with a barge pole. Totally overpriced crap engineering.