Quite rubbing, or rattling sound that is constant, not affected from road cond

Hello, The rubbing noise on the left in your Cadillac Eldorado is possibly from wheel bearing or from irregular tire wear. A simple test drive will determine what testing if any is needed.

Thanks for your input. Its not the bearing or tire. it sound like a vibration in the car from the road, wind & motor running causes some two surfaces to touch and vibrate together (a plastic shield or thin metal deflector or something) and make a quite noise. I have checked the suspension. it is not a knocking sound, not grinding sound, not a metallic sound our deep rattle against the frame.