Hello, again. Your thread (partialy ) motivated me to get the Non-Sport G37x. I test drove a G37XS before I bought. I also really wanted the wood trim.

To your issue, I would recommend getting Micheline Pilot-Sport A/S (all season) tires. I have had them on my BMW M3 (E46) for years (in the winter). I use separate 17 in wheels for winter and the ride is a bit softer. The Tire Salesman indicated it's not always the wheel size/profile, it's the tread on the tires. On an M3 that means a lot, since the suspension is very, very sporty (stiff). The handling should not suffer much and you will get better traction on these tires.

good luck