[Topless in Cali]

You can run 20's, but the tire is like a 25 or 30 series, so I hope you don't live where there are too many pot holes! I believe the size that fits is a 20 X 8.5 with an offset of 30-35 using a tire like 225/30/20 or 235/30/20. The ones I saw the guy had to use a 5mm wheel spacer to clear the brake caliper and strut housing. You would not have any strut housing issues though if you used a coil-over system that has the real small spring perches like the BTG coil overs.