[woodsman]

Sounds like a slipped belt but that seems unlikely. In a tight U-turn, the wheels are actually running on different trajectories and can cause some scrubbing but backing straight out you shouldn't feel anything. It could be a worn bushing on the trailing arm- maybe....Some tires flat spot after being parked and I wonder if that's what you're feeling when reversing? These cars have a lot of caster ( compared to what I've owned) and this puts things in an awkward position when reversing as can running a different offset from stock. I'd get an alignment at the best shop in town or at least remove both front wheels and stress the bushings this way and that.