Hey folks,
Finally got new tires on a set of BMW 313 wheels. These are 18" rims instead of the Z4 313s, which are 19". I had the 296s on the car and combined with the run flats the back roads were pretty brutal.
I was worried about the offset of the wheels vs the stock rims and had purchased 2 12mm offset plates for the front wheels. It turned out that I didn't need them, they sit in a little bit more than the original wheels though. There is no rubbing and I still think they look good on the car.
I had Michelin PS2s put on the new wheels, they are a world of difference from the original run flats in terms of ride compliance. The grip seems great too, but I haven't really pushed it yet. We will see if it still understeers a bunch in the corners, which I do expect it to. Oh, the PS2s I got were 225/40 on the front and 255/35 on the rear.
The fit on the front brake calipers was pretty close though, but the stock 18s fit the same way as well.
Ron.