Parking brake cables. Due to the aroma of hot brake pad following a below 0 snap after a warm spell Ken suggested try replacing the cables first. 45 mins to swap the cables and 3.5 hours to dismantle and reassemble the centre console (including taking it in for a good scrubbing). Putting the support for the centre armrest over the adjuster nut for the cable yoke might have been convenient for the factory but does mean taking the trim off to get to it should you need to get to the parking brake cables. But the brake is not dragging anymore.