I bought my RX400h in July 2011; less than 3 years old. It was still under manufacturer's warranty. I pointed out the corrosion on the wheels. I was offered a refurb; could not wait 3-4 days--I did not have a car. Offered wheels from another RX400; accepted, although they were not as bad, but still minor corrosion.
The corrosion got worse. I asked another Lexus dealer what could be done. He approached Lexus UK; Lexus said they would replace 2 wheels--because I was the second owner and it was outside the 3-year manufacturer's warranty. I reapproached the dealer I bought it from; the manager stated that he could not approach Lexus UK at the time of purchase, as I had just bought the vehicle. But, had I asked about the wheels a little later, and before the manufacturer's warranty expired, he would have gone back to Lexus UK, and the wheels would have been replaced. An opinion; I was misinformed at the time of purchase--totally unacceptable, and unprofessional, customer service/relations.
This is still an ongoing, and unresolved issue.