I have a 2001 Lexus IS300 with 348K miles on it. I have owned it since Nov. 2016. It is Spectra Blue Mica. It had 238K miles on it when I purchased it. For several months now there is a loud squeaking noise coming from the rear of the car at only 35-45 mph. I have had two different repair shops look at it on a lift and drive it, but neither of the two repair shops can figure out where it is coming from. My brakes are still good. No issues with pads, calipers, or rotors. Rear shocks are just about six years old, wheel bearings are good, and suspension is all tight. Tires still have plenty of tread and only three years old. I have three year old Touren wheels on all four. Any ideas why the squeaking only at 35-45 mph?

 

Have you tried to spray silicon spray on the bushings? They will squeak when old or real dry.

 

I will try this. Thank you.

 

Upadate: doing an alignment on the rear wheels seems to have fixed that annoying squeaking.