I have been dealing with the faulty wiring issue in my 2012 mk2 twin door, which coincided with a flat tyre and I couldn't open the boot to access the spare/wheel lock. The nice man from the AA managed to find a way. When you remove the trim from the saloon boot lid, there is a white lever which is designed to have a cable release attached. You can either attach a cable and route to a handle in the lid, or cut a slot in the trim so you can use your key as per the latest manuals to move the lever. The image is upside down as it was taken with the boot open.