I took my RX400h to the local Chips Away, who were offering a special deal on refurbing alloys. The guy was really good, and said that he has this problem all the time with Lexus, and whilst he could do a quick refurb, it would not last. The Lexus alloy is so bad, that if Lexus will not provide a replacement wheel, then they need to be fully sand blasted, without the tyre and valve, to take all the old alloy off, and re-alloyed - he quoted me £65 per wheel plus VAT - I have not yet had the time/bottle to do this, but they are getting worse every day, so I will have to bite the bullet very soon. I cannot see the point in simple refurb, as the alloys would never restore properly - full blasting and re-alloy seems to me to be the only solution. As other points on this BB have said, Lexus just do not want to know.