Welcome to the site! Your 2006 330ci is an E46 chassis so I've moved your thread from the F30 chassis forum over to the E46Fanatics wheel and tire forum.
A worn shock would not cause that excessive tire wear, sound like you should replace both rear shocks, the shock mounts (they're a wear item) and then have the car aligned. What size tires are on the car? You can run the same size all around.