Someone I know bought a 335d M Sport 3 years ago, wasn't made aware that because it had run-flats, that they were not repairable in the case of a puncture.
In the course of the first few months of ownership picked up two punctures, then just recently at it's first MOT it was failed because it had a bleb on one of the tyres, but worse than that, the alloy was cracked.
They wanted him to pay £500 odd for a new alloy but claimed it wasn't fit for purpose with BMW fitting the cars with stupid tyres when our roads are pothole ridden, ended up only having to pay for the tyre.
He enquired about retrofitting normal tyres but was told that it would void the warranty, surely not?