Just picked up my 2011 L322 Supercharged from the dealer after having the emergency parking break module replaced. According to the service tech, wires checked out fine. Rust buildup was removed, had to lower exhaust, sub suspension and rear breaks an calipers to address problem and replace module. Upon pick up I am hearing a creeping sound coming from the rear boot and breaks whenever the Rover moves or the breaks are applied. Note both steel break lines were replaced two years ago.
Parking break module was $1,731 and labor was $ 1,350. With tax total was $3,350.

Rover is in otherwise mint condition always serviced by certified rover techs.

What might cause this new creeping sound? Rear sway bar bushings, calipers?