I have an RX400H, 57 plate with 60k owned for just under a year. Great car and I will keep it for a long time. Only complaint I have is the Sat Nav which is well out of date. Lexus won't sell the UK update disc on its own but insists on selling the full European set which is expensive. It doesn't do full postcodes so it is actually cheaper to buy a sat Nav from a retailer with greater functionality, large screen and free mapping updates. I have written to Lexus pointing out they are missing an opportunity to sell UK discs and make a small profit and are encouraging owners to buy substandard upgrades on the the Internet or separate sat navs. They won't relent.
If you are buying from a dealer try and get the latest discs as part of the deal.