I have a D2 2003 and have mine wired as follows.
4 Gauge cables from the main battery (100 A circuit breaker on the positive cable located in the compartment on the battery frame) run along the top of the chassis rail back to the RHS corner panel and then forced through the rubber grommet for the tail light loom. This was a ***** of a job but worth the effort. Hint, use the tip of a silicone or similar "goo" product cut down and placed over the tip of your cables to push them through.
This was then terminated with a 125A anderson plug inside the little vent like panel on the RHS at the rear of the cargo bay with enough cable to reach the back of the seats.
I then wired up a redarc unit and another 100 A circuit breaker in a plastic kitchen container (tupperware if you are game) with wires in and out through the sides.
This then connects to the battery and the fridge . The battery is a Length 511mm X Width 110mm X Height 238mm 100A deep cycle AGM sealed battery ($160 second hand on ebay) and it sits between the vertical edge of the fridge and the angled part of the cargo barrier (or seat if you dont have one).
This way the battery and fridge are independent of the car and can be removed wien not needed to save lugging around excess weight for no good reason.
The other benifit is for $45 I have put the base cable/circuit breaker/anderson plug in my rangie and can have dual battery set ups for both cars at an agreeable price.
The battery needs a couple of hours car time to fully charge (about 4 seems to be needed), and keeps my 76L explorer fridge freezer going for 36 to 48 hours in 33C heat. Remember the 125 A alternator on the disco does not mean you have 125 availlable for charging as the car uses a lot just running and seems to only have a little spare capacity (25-35 during the day and even less with the headlights on).
Hope this confuses the issue even more.
