I had Bridgestone runflats on my Z4 and they were wretched. While they ride hard, they wear fast, too. Check the ratings. The PS2s have a higher treadwear rating. They cannot be repaired under any circumstances, at least based on my experiences. And while BMW has this pact with Bridgestone, I would note that the M3, Z4 M coupe came with regular tires, not runflats. That has to tell you something. I wouldn't put them on my CS if you gave them to me.

__________________
'07 CS, Meteor Grey, stone grey, 19" Carrera Sport with meteor grey spokes/polished rim, headrest crests, bi-xenons, Bose, power seats, rain sensor, fire extinguisher, heated seats, dimming mirrors, FabSpeed Maxflo II catback
'06 CLS 500, white, beige
'04 Black Ranger Edge