I know this may sound really silly, but switch of your heater fan in the cabin and try a few left turns with it off. I had a similar problem in a BMW 525. I had a number of BMW technicians trying to diagnose the noise which they all said like me ,was coming from the nearside front suspension. After many inspections and road tests it was solved by one from a different garage who had experience of the same fault. When the fan bearing gets worn it allows the vanes of the fan to slide to the end of the bearing shaft and rub against the mounting. I don't know if Lexus fans are similar but at least it costs nothing in tme or money to find out.
Good luck. Peter.
I have a similar problem with my is200. its a hissing/rubbing sound when I turn left coming from the front drivers side wheel area. I have been told anything from a slipped barke pad to cv joint to back plate!!!!
CV JOINT CV JOINT on the front??????????????????????????? the is200 doesn't have one as its rear wheel drive!!!!!
yes the fact that it is rear wheel drive did cross my mind, think it just goes to show you can have all the forum advise in the world but even mr toyota mechanic for 4 years can't tell whats wrong unless he is looking at the car. put mine into a garage on friday will post what occurs