If my Z was a daily driver and I didn't swap wheels for the summer months, I would get Continental ExtremeContact DWS tires. They are ultra high performance all season tires. They're good in the cold, wet and light snow. I have a set on my stock rims for the colder months. They work great for the mild winters in the Hampton Roads area. Down side, because they are all seasons they do not have as much grip as a high end summer tire in the warmer months. However IMO they have more grip than the OEM Bridgestones that come with the car.