I have owned my RX450 H for 9 months. Its 8 years old, and has just clocked 100,000 miles. It came with a full Lexus service history, and everyone I spoke to said that having a relatively high mileage car wouldn't be a problem as they rarely developed mechanical faults. Just under a month ago I was caught on a B road in torrential rain, and the road ahead was flooded for 50 yds or so. I watched a Ford Fiesta drive through it slowly, and gauged the the water depth to be no more than 4 to 6 inches max. So I took it nice and steady, maybe 10 mph. As soon as I reached the other side the dreaded "HYBRID SYSTEM WARNING" light came on.... On the Monday morning I took it into my local garage, who are pretty experienced with electric and hybrid vehicles. They checked the batteries ; all fine, but they couldn't trace the fault code for one outstanding system.. So next part of the saga was to take the vehicle to the Lexus Main dealer in Cheltenham.. At this point, worried about the rapidly escalating bill, I contacted my insurers, Direct Line, who seemed happy to accept the claim as ' accidental damage", but the claim would be subject to a vehicle inspection by one of their own engineers. I have heard today that they have declined the claim as they could find no evidence that water caused the damage. I am now faced with a bill for a complete new electric motor and transmission, which will be around £6,000 . The engineer phoned to say the they had found lots of metal fragments in the oil, causing the motor to fail.. I find this all highly suspicious ; the odds of having the HYBRID FAIL light come on after 100,000 miles , immediately after getting the bottom of the car wet are so unlikely... Lexus did offer a discount on the purchase price of the motor however... is this a problem common to this model I wonder ? ( I found Lexus promotional photos of RX 450's being driven through far deeper water too.)