With couldn't agree more Phil.
Just because a Lexus dealer has one on the forecourt it doesn't mean it will be a pristine example. When I booked mine in for a service at Lexus Plymouth recently I had a look at what they were offering.
I felt a justification for the time it took me to find a decent RX, when a younger version of mine being offered for £5k more than I had paid and was in a much worse condition. I noticed that it had been resprayed near the fuel door, had no rear bumper scuff protector plus there were scratches and nicks all over the paintwork. Clearly a valet had been done on the interior but it couldn't hide the fact it had been, shall I say.......well used.
There are decent private ones out there, but they will take a little longer to find and you will have to be prepared to travel.