If it is a V reg, then most unlikely, unless of course it was registered before the 4th of sept 1999.
In any case if you bought it from a Lexus delear, then it should have a one year warranty on it.
If the warranty is still valid, then all you need to do is contact the dealer and male the claim before it runs out, as long as you do that you are covered even if the wheels are not available now.