I have an 08 Cooper S with runflats and have come into some snow tires already mounted on 15' steel mini rims (the tires are R15 65 175 I think).

Are there any issues in switching over?

 

Try a search here on NAM, but I don't think there are any 15" steelies that will fit over the R56 MCS brakes. There are some aftermarket 15" aluminum wheels that fit though.

Jason

 

You can try a test fitment before you buy.

I don't think it will fit.

Your bolts are 14mm wide and the steel wheel might be made for only 12mm bolts as on the older MINIs.

Your front brake calipers are larger and won't accept a standard MINI wheel- more clearance is needed. Back might fit.