A couple of degrees out would produce pretty extreme wear on both rear tires and it would probably not track straight. Since the Hybrid uses a torsion-beam rear axle, about the only way to get it bent like that would be to slam into a curb really hard. Time to get an alignment check...

 

No curb slam ever happened. It does not pull to the left or right either. It is only a very few degrees, but as a former engineer, I notice.

 

It would be hard to tell if something has failed but might be relegated to taking it to Ford for an alignment service in case there is. Unfortunately my local dealership wanted $170 for an alignment BUT if I bought a set of tires it would be $90! As Red Ryder suggests, about the only to confirm is get an alignment check. Be sure to get a before and after printout of results

 

I won't tell 'em I want alignment. Just tell them to fix an anomaly under warranty.