Much of the excellent handling characteristics of an Imp can be attributed to the good location provided to the rear wheels by these wishbones, compared with the leaf springs of trailing arms of its rivals.
This excellent, if rather expensive solution was arrived at after the design team was involved in a serious accident whilst taking a bend at 30mph in a swing axle Corvair (they were evaluating).
These wishbones are generally sturdy and trouble free units unless suffering from accident damage or corrosion.