275/35/20 hi perf all seasons is where I settled. trying to decide now if i can wait till spring since i have 12k on the p-zeros. i will never see snow, but the cold temps are troublesome.
I'm debating on widening my rear Foundry wheels as well. I can't help but worry about trade in value in a couple of years. I feel like I'll get jipped if I don't have the stock wheels.
I have never been able to justify the cost of aftermarket wheels and tires. All the wheels I like are at least $300 per so that's around 2k+ for wheels and tires. NUTS!
275s are pretty wide on 9" rims. I wouldn't go any wider than that, and I don't think I would go that wide in front because steering response is soft. Te car will drive better with 255s steering. (I had 235s on 9" rims on the front of my Fox, and the sidewalls were nearly straight but the wheel was a bit wider than the tread, making a very stiff tire. Steering response was excellent, best I have ever had on a Fox. Same idea here.