either you do a lot of handbrake turns, leave the handbrake on slightly one click etc while driving around, maybe the fronts were changed before say at 12000 and the rears were at 50% then? I think the rear brakes are used with the rear torque biasing system so maybe they have been applied a lot, do you use it in track/drift mode/corner hard a lot? Hill start assist holds the rear brakes on a bit I think too when you do a hill start so maybe they have been dragging/slow to release?
No Mods. No rockers. Just a chunky knob.
Std as Ford intended, but with a space saver wheel and jack and nuts and wheel brace. oh.. and flaps, a man has got to have flaps.