I realize this is next to impossible to diagnose without seeing the car, but I have a clunking sound when driving the car over very slightly rough roads. It sounds like it is coming from the rear. With the car up on a hoist, I cannot find anything! Exhaust is not hitting anything. All the rear suspension bushings appear good and tight. I even checked the spare tire and jack. Also checked the upper shock mounts (still have the adjustable ride control shocks, but they feel good and "firm" vs "normal" appears to have no effect). This has been going on for about a year. Driving me crazy.