[Richbot]

You don't need to match the stock diameter. The car is designed around a square snow tire setup from the factory and the stability control is very tolerant of different tire setups. It's a non-issue IMO

295/30 is shorter than stock, it's shorter than the stock front tires for that matter, but again, who cares. Rear gets lower, shorter gearing, these are good things fro going fast.

If you do want to match the stock diameters and go wider with 18's, 275/35 and 295/35 front/rear is about the closest you can get, but PSS is the only decent summer tire sold in those sizes currently and it's an old man at this point

Keep in mind the PS4S comes in 275 and 285/35-18. 275/285 is the same stagger the F90 comes with from the factory. The 285/35-18 is just as "big" a tire as a 295/30, because it's much taller. For a rear tire, bigger diameter is helpful for traction, especially if you're making a lot more power than stock

I'm using 275/30-19 PS4S on 9.5" ET23 stock wheels, square, with a 5mm spacer in the back right now. It ahs plenty of rear grip, if you're just wanting the bigger tire because you want it to look meatier, I get it, but if you're near stock power 275's square is plenty of tire for a street car, and you can rotate

Also keep in mind, if the concern is rain traction when you think "street friendly", wider is generally not better in the rain