My 2001 LS430 developed 2 rust spots on the drivers door just above the rubbing strip. when Lexus Birmingham checked it out they took photos and had confirmation from Lexus UK that it was still covered under the 12 year anti-perforation warranty. The confirmation took a few weeks to come through but once it had my car was in for a brand new door. Same happened on the passenger front door about 18 months later and that was replaced as well. It was deemed a manufacturing fault. I am very surprised that the dealership you took it to never investigated this further and were just so candid with you. I would make enquiries with other dealerships in your area and see if this specific fault reported before. They should have at least taken photographs for further investigation.
