Anyone running 17x8.5 ET32 on an R52? Does anyone know if they will fit?

 

Yes, it should fit with stock suspension.

Inside you have stock clearance but outside your wheel sticks out 26mm or 1" more than stock which is fine using stock tire diameter and stock suspension for added clearance.

Note that compared to stock wheels a 17x8.5" rim is much wider and could be heavier.

You can mount the following tire sizes using stock suspension:
215/45-17 fits rims up to 8" wide but can be stretched to fit
225/45-17 is a bit tall at 25" tire diameter but possible
235/40-17 is fine
245/40-17 is fine, note this tire is 40mm wider than stock, much less clearance on lowered suspension

 

Do you measurements are? I plan to change the suspension to a coilover system.

 

The wider tire you mount the less clearance you will have.

If you get ride height adjustable coilovers that would be best since you can lower the MINI to the height enough to get clearance for the tires.

Inside the wheel well you have enough space- it nearly stock, outside you have pushed the wheel outward so the tire have less clearance.

You can also mount the more narrow tires for more clearance and you can use more negative camber to get more clearance but you will need adjustable front camber plates and adjustable lower rear control arms.

Use this calculator to see how your wheels might fit-
http://www.rimsntires.com/specs.jsp