The police would be doing a whole lot of re enactments at the behest of the DPP along the lines of Karen's exit from that house.. once it is agreed that she ' didn't walk out to clear her head, ' then she must have been involuntarily transported. From the garage . Once the idea of her leaving under her own steam evaporates then not much is left in the way of possibilities.. Borce didn't carry her, or wheel her out in wheelie bin , or balloon lift her from the back yard, or tunnelled her on a little rail line under the house, he did what most murderers do, ,he shoved her in the boot of the car, her car most likely, but it is still possible that the Merc drive might have been a ploy... the 100 missing minutes, could he have doubled back and drove out the other car with her body in that boot?
he thinks he has established 'Karen' tootling up the Calder, now it's time to get down to business. .. it isn't improbable, and even more so if there are 2 drivers.........