In late may 2015, i noticed a bubble in my driver's side rear tire. i took my car to the dealership and they insisted that it was my fault. i had to pay to replace the tire. now, not even two months later, i now have a bubble in my passenger side rear tire. the tires are from the same batch. the tires are continental contiprocontact 215/55r16 93h tires. with these being potential blowouts, these tires are unsafe. the bubbles must be a defect. i never had issues with the tires on my old car.