I´m sorry, but what am I missing? The whole story sounds like an advertisment FOR runflats. You had a puncture and thanks to the RFT you could safely continue your journey to your destination (no dangerous tire change at the roadside), the car was driving safely even at the time of the deflation (which it would not have with non-RFT), you could postpone taking care of the problem to the next morning. BMW Assist performed well in guiding you to the next dealer.
There is no reason to believe the RFT´s caused your problem, but they certainly did lessen the impact of it.
Excellent performance and just a reason to thank RFT.
The only trouble you experienced was from
1. The poor availablity of a replacement (Which will hopefully become better in the future with more cars beeing equiped with RFT´s)
2. Cost, which is bad but then, flats are rather rare, so the chance of having to spit it out are rare. If you´re worried insurance is a solution, but then, insurance companies allways make a profit, so insurance is never a good deal. I only take up insurances for potential losses I cannot afford (i.e. whole car). I think most E90 owners could afford a tire replacement without having to postpone their holidays
