I have a 2005 RX 330. I had it in the mountains recently -- driving over gravel roads, nothing too rough. I had just recently had a rear tire repaired and remounted. When I got home, I began noticing a creaking noise coming from the rear driver's side. It seems to occur the most when I'm backing up down hill, taking turns, braking to a stop, driving over uneven pavement (like waffley parking lots, etc.). It happens even when I'm not pressing the brake, so I don't think it has anything to do with the brakes.

Could it be due to something that happened when the tire was repaired? Or is it more likely to be something that happened when I was driving over the gravel roads in the mountains. One other thing that happened is that I was backing up to a low stone wall and gently scraped the underside of the bumper. I don't think I hit the tire when I did this, though.

 

Creaking? maybe your bushings are to blame. Take your rear wheels off,and spray some silicone spray on the bushings. See if that stop`s it. Could be a strut mount too.