I took my Crosstrek offroading for the first time yesterday after the storm we got in the Northeast and had a blast in the snow with my first AWD car. Today though when doing highway travel the car was vibrating excessively to the point I pulled over at a rest stop to see what was wrong. It looked like it was packed snow that had frozen over that I cleared the best I could but I was still vibrating a lot at highway speeds afterwards. Assuming it still is just the packed snow and ice on the tires that is problem am I hurting my car at all or its AWD system to be driving it like this? It's currently ~20F out and I have no way effective way to get rid of the snow and ice.