I purchased new pirelli pzero tires from my local bmw dealer. the rear tires exhibited intermittent air loss and were replaced by the dealer because the dealer believed they were damaged during installation. the second set of rear tires also exhibited intermittent air loss. the dealer believed the wheels were damaged and causing the air loss. i had a wheel specialist inspect the wheels, and they found no defects to cause air loss. the wheel specialist found the tires to be defective as they have excess material at the bead that prevents proper sealing on the rim. the wheel specialist attempted to remove the excess material from one tire to determine if that would improve the problem, which it did to some extent. i called pirelli and notified them of the problem, and they stated they would replace one rear tire under warranty but not the tire that was worked upon by the wheel specialist. in summary, i experienced two sets of defective pirelli p zero tires leading me to believe there could be a problem with additional tires. i have video evidence of the leaks seen during a leak test.