Our long term plans include adjustable spring perches so we can lower the car for proper track cred.

Also in the last AutoX we had a bit of tire rub - nothing serious, but we should address it.
Our current condition - 275/35s on 18X10, +40, -2.5deg camber. Here's our tire clearance in the front:
With suspension near full compression:
It currently doesn't rub, but you can see it we lower the car, it certainly will. The rear is a little tighter at the fender lip and rubs slightly under full compression.
Here is the inside clearance:
I don't thing you can get any closer than that! Notice that the 275s are actually stretched slightly. I'd like to run 285s because they are a more common size and they fit the wheel better, but they would definitely rub the knuckle.
So the plan is the run 5mm spacers on the front to provide enough clearance for 285s at the knuckle; and create more room under the fender by trimming and adding flares.
Most of the "universal" flares on the market are either far to small for the width of our wheel opening or they are very short and just cover the top of the tire. After MUCH searching, I think I've found flares that will work. They match the fender arch very well - all the way around. I will provide full details after the install.
CR