I have the wider rear axle, so was concerned about the width I could use on the rears. Plus the rim width is limited to what they will accept.
The 235/60-15 Yoko's I am running currently, have no issues. No body rubbing even over speed-bumps with a passenger. and a full tank of fuel. If I roll on the power, rather than stomping on it, and don't slap shift into 2nd, tire spin hasn't been a concern. Probably want something wider if i was drag racing mind you. The car feels balanced, and handles wonderfully through tight winding roads.
It looks like Cooper Cobra's is another choice available in the 15". I run the Pirelli's on my 1980 Malibu, and have been pleased with them, but was curious how they may be on a roadster, being it's a whole different class of vehicle.