I brought the car into a heated garage for a few hours this afternoon inspected the mounts and washed off the accumulated salt and grime. I also changed out the left front axle with a nice tight one that I had set aside. When I left there was no snow or ice on the car, but when I got out on the expressway the vibration was still there. The rear shocks show no sign of leaking but are original. They are on my to-do list, but I hadn't considered them as the culprit to my vibration problem. I could be wrong.