2002 Saturn SC2 Vibration independent of RPM

New issue in the past week. Vibration underneath the car is noticeable in the wheel and pedals. It is not a violent shaking like a bad alignment problem, but does increase in frequency up to at least 50 mph. Seems more noticeable when braking to a stop. Not tied to RPM: the vibration is the same gliding in neutral at 40 mph and 1000 RPM as in 4th gear at 40 mph at 2000+ RPM. Just got a balance/rotation/alignment which did not help and may have made it worse. Tires are fine. I have been wondering if this could be a wheel bearing issue or could be related to rotors/calipers. Just a gut feeling. But it "feels" like something is rubbing that shouldn't be. The sound is not loud, scratchy, or squeaky. It is rhythmic. I have also had a history of having to replace motor mounts on this car, but that does not seem to line up as well as being related to these symptoms. I have always taken this car to the dealer and do not let problems go unchecked.

With saturn dealerships gone now (I go to the GM dealerships where the saturn techs wound up) I know they see dollar signs in their eyes when I show up and I want to be able to focus attention on the right part of the problem. My parts are never in stock and I also want to get the right ones ordered on the first try. This problem started exactly 1 week ago after I left the dealership when my radiator fan was replaced. It seems hard to imagine this problem is related to that repair, but I suppose anything is possible. Other than this, the car is running fine and still gets 27/37 gas mileage, so I am hoping to keep it running a few more years yet. I sold my last saturn with 222,000 miles before I got this one.