Check your strut mounts before more expensive repairs
If anyone is experiencing noises when turning, maybe also on bumps, check the strut mounts and strut mount bearings. Replacing one solved a problem when many where talking about steering rack and pinion assembly, struts, or other expensive parts.
Also, someone here on clublexus said his strut mount was so bad that the only thing holding the car was the weight of it on the spring. Go figure.
Hope it helps!