Ive got a 2007 sport MM and noticed 1 of the wheels has started corroding, this might sound dumb will they just repair the wheel or replace it, if replace it will they replace all 4 or just the one thats knackered.

They will/should replace it.

I've got the same problem and relying on Lexus to replace all four as they did on my IS200 Sport.

No quibble at all. Ive just had all four of mine replaced at Edgware Road. There was corrosion/bubbling on the front two and their aftersales just ordered 4 brand new alloys from Japan. Took two weeks to arrive. Car looks brand new again.

You should only get the one that has a problem replaced,many dealers just do all 4 or 5.Dont be surprised if you are changing them again before the warranty runs out.

i saw boxes at the dealers parts dept with alloy wheel refurbishmentstamped on the side,many boxes,i don't think that we all get new ones?

I'm pretty sure they do refurbs as they last longer than the new ones

i was recently told by a toyota salesman that long standing contract with the manufacturer of the suspect alloys is soon to end.so maybe quality will improve with future suppliers.

yeh, call the dealer and get it booked in.

ive had mine from new back in sept, 06 and just this april i got all 4 alloys replaced under warranty because of the meta bubbling up

Bristol dealership told me today they replace with new, not refurbished, and will therefore only replace those showing corrosion. Also told me Lexus GB have had so many complaints that they're on back order now, so may be a long wait. Also said Lexus only get this complaint from the UK..I said if they had got it from the USA they'd have done something about it by now..he said he couldn't comment on that .
However, he thinks the situation is about to change so advised it may be worth waiting a while..... May be referring to the change of manufacturer that dgman noted.