I have a 2005 Mk3 GS300 SE-L. I bought it privately at 58,000 last year. The documented service book was not available from the owner, I was going to walk away from the possible deal! I verified the mot certificates and mileage online whilst looking around the car. It all checked out, the overall impression was that it had been well maintained; I was confident in the car as it was a steal (I offered the owner a lot less than the asking price) and in beautiful condition with fresh oil showing up on the dipstick.
The day after I bought it I contacted Lexus who sent out a replacement service book stamped up to 48,000 before the then current owner who had it serviced by a local mechanic. I also checked the recall history with Lexus which was up to date.
I am now at 62,000 and make sure that I use it for decent journeys (not tootling around town for 5 mins), in Scotland where I live there is little in the way of traffic which allows me to cruise easily. I just covered 260 miles with 5 adults who loved the quiet unflustered ride and the leg room in the back.
Everything works on the car apart from the drivers side puddle light on the mirror. I may have to replace the rear shocks as the service inspection showed a possible leak on both. I had a Volvo V 70 T5 before which was so powerful and I thought I'd miss it but I have to say this, the Lexus is a joy to drive, so relaxing and power when you need it and also economical!
I did take a risk buying privately but it was worth it as the car has proven excellent.