Part 2 of the new wheels – OEM X GSR wheels to use as track wheels. I would be running the 265 width for SCCA autocross, but the limit for AWDs in street and most enthusiast classes for track were 255s. The X GSR wheels ended up being a good compromise that would be relatively cheap and light, and would clear the brakes. They are 18×8.5, so a little narrow for autocross, and I plan to test how the 245s fit on them first, before going to 255s.
Update 4/2/18 – 245/45-18 RS4s have been mounted, will use for track days. Will break in at the next few autox events first and see how they do. The fitment is very good, plenty of clearance to fenders front and rear, and the suspension as one would expect with 20mm narrower tires and 1″ narrower wheels.