When I got my IS250 it was from a Lexus Used Approved dealer, so came with a 1 year warranty. About 10 months later, the front wheels showed signs of blistering so got them replaced for free. About 18 months later the new ones started to blister, despite regular cleaning/waxing. Although that was a few years ago I doubt the issue has since been resolved. I am also thinking about buying a new set and getting the current ones refurbished for winter tyres and will definitely get them coated with sealant prior to use.