For what it's worth, I recently had a very similar problem with my 2001 LS430. One of my tires was always running low on air, so I took the car to the dealership to see what was up. I figured it was a tire problem - I never even thought the wheels would be the problem. They told me the chrome was corroding and peeling and that it was creating an unsafe condition. They even told me they would not permit me to drive the car off their lot without replacing the wheels. They quoted me a price of $2,800 to replace all four wheels, which I quickly rejected. I love the car, but this is very frustrating.
