I have a 2004 Subaru Outback with 120,000 or so miles on it with very few problems. For some time now I have heard a sort of thumping like a tire sound on the highway. I've checked the tires several times and they are okay.Yesterday, when we returned home I noticed in our driveway, which was a little wet and soft, so the tracks were real clear, that what looked like for every tire rotation the track was rough like the wheels were dragging. I don't know how to explain it any better. If it helps, I had a front right cv joint replaced about a year ago which is about when the noise started. Any help would be very much appreciated.