I drove to a pet store only to find out it was a dump. When I left, the car was rough on the road, and we could hear a clicking sound. I checked the tire to discover tar and small rocks fully covering ~6 inches of tread. Any idea on how to fully get it off, as easily as possible, without damaging the tire? I could take the tire off, and scrape it off, but I do not look forward to that kind of option.