Haha 3Series, that's a good way to look at it!

If you're in a car that doesn't have a spare wheel (i.e. a 7 seater X5) then what's the benefit of having runflat tyres over standard tyres and a Mobility Kit? As far as I can tell, runflats won't protect you from anything more serious than a standard puncture anyway, which the Mobility Kit should be fine for. Am I missing something? Obviously having a spare wheel is infinitely more useful but if you don't have the space for it in the car...