Then they put it through an alignment diagnostic and I was told the front end was somewhat misaligned but the back end was fine (Again, why wasn't this discovered when I took the car in for new tires?) They recommended a front end alignment to try to fix the “bump bump” on the right rear tire. I had that done, but it has … He couldn't explain it….saying, “that's very odd“. So, does anyone have an idea of what's going on with this right rear tire? The other three look fine. This is the area … …

See the article here:
strange problem with rear tire – Tires & Wheels … – Car Forums