I have recently replaced all of the rear control arms, all 4 coil springs, a ball joint, a tie-rod end, the steering idler arm bushings and all 4 tires. I also had a recent alignment. The car runs straight and smooth as fast as I care to go.
Based on the symptom getting worse as the car is driven longer, my thought is that this is a rubber part failing. I would appreciate any thoughts of where to start looking and how to identify whether or not the various parts are failing.
Thanks,
Robert