Not sure if the runflats on the Z06 are different to those on the stock LS2 C6 (I'm sure they are, with wider arches to fill but can't be bothered to look up the numbers) but the stock car handled beautifully when I tested it at GMs media day at Circuit Ascari in Spain. As far as I am concerned, those tyres work very well indeed up to and past speeds that most drivers could ever get near to on the road. Maybe other tyres would prove slightly better, but the run flats handle fine, and leave you space in the trunk.