Yeah, I'm on my fourth Mini Cooper, and they say that here, too. You cannot repair run flats. I still like run flats, though, because I've read that they don't "blow out" if they take damage at 70 mph. That's good insurance, to my mind, so I'll put up with them.
PS Don't go to eTrailer dot com for a tow hitch for your Mini Cooper. I've had two hitches from MiniDoMore with no problem (mnidomore.com) but wanted an easier installation with this car. Not a good idea. The hitch attachment bolt broke the aluminum frame of the car. Now I can't even get my money back, because the hitch was not damaged and so apparently isn't at fault. (Nevermind that it was THEIR installation instructions that I used.)
The car isn't badly damaged (just a torn through bolt hole, that was previously capped over) but I'm out the cost of the hitch, plus I have to get another and install it. Going with only
MiniDoMore from now on. And I'm making sure to spread this story across the web, too. The other web site specifically recommended that hitch for my year, make, model of car. NOT good service.