I've no doubt they could be fitted but the question I'd want answering is what would run flats do to the ride comfort.
The early run flats on BMW's were dreadful in terms of ride comfort and people couldn't wait to get rid of them and fit normal tyres to bring the car back to a civilised level of compliance. Cars with run flats do now have improved ride comfort but is that improvement in compliance due to the tyre or is it the fact that the cars suspension has been designed specifically for using run flats. If it's mostly the latter and I think it is, then fitting run flats to a car which hasn't been designed for them may take you back to a poor ride.
I've driven for a minimum of 31 years (that's as far back as I can remember with absolute certainty) without having a puncture, so if it was me, I'd keep the ride comfort and risk the can of gunge or buy breakdown cover.
Results of a quick Google on BMW and runflats:
BMW has largely moved away from using run-flat tires primarily because of customer complaints regarding their harsh ride quality, increased wear and tear on the tires and suspension, and the higher cost compared to standard tires