Hi all,

I'm the proud new owner of a beautiful 2006 RX400h (Roxy) in fantastic condition. The only thing that seems off is that the steering wheel clicks/thunks when I'm stopped or going at a low speed and turn it just slightly. This is different than the "ratcheting" clicks that disengage the turn signal, and I can feel it through the wheel. There doesn't seem to be any impact on steering, but I'm a little worried that this might be an early symptom of something more problematic.

Has anyone else had this?

 

Yep.
ISS.
Intermediate Steering Shaft. Plague on GM and Toyota cars. You can "milk" it to reposition grease inside but for the effort involved to do this, it is about same labor as replacing entire piece.