I picked up my 05 roadster in July - car had 28,000 miles with org. conti tires,
Tread on fronts seemed ok, rear tire worn, real problem was that both rear
tires had HUGE sidewall cracks - about 1 1/2" - made me way too nervous to drive on them - replaced all 4 with Goodyear F1 D3's.

Tire were incredible all summer and early fall - never lost traction, held the road like glue, quiet and ride improved somewhat over the conti's.

This is the 1st time I have used summer performance tires - wow once the temp drops below 40 - ride is harder; traction lite comes on - alot and just don't feel as confident that the tires will hold like they did in warm/hot weather.

So far have added about 8,000 mile to the car and the tread seem to be holding - but have no high mileage expectations for these - maybe another 12,000 miles and WOW - I get to do it again!