Have you considered the FEH? I won't argue that it is as nice as the Lexus or Toyota, but even fully loaded it comes in around $6k cheaper than the Toyota and gets about 4-5 mpg more.
At about the same size with side curtain airbags, it's rated well in crash testing, but not as well as the Toyota - except in the case of rear passenger side impact protection where the FEH scores slightly better. But then there is the rollover factor which favors the Toyota.
http://www.automotive.com/2005/12/to...ety/index.html
http://www.automotive.com/2005/12/ford/escape/safety/
So if frontal crash protection is #1, it's a no brainer to stay away from the Ford, however I could not find RX400 test data. But know that you are making the choice between you and your rear seat passenger's safety. Ok, that's probably an unfair guilt trip to lay out because changing the testing method slightly could skew results considerably. What else can I say, we've got the FEH.
Likewise, towing more than 1000lbs throws the FEH out of the running.