12 Volt Auxiliary Socket .
I found that the 12 volt socket in the door was very inconvenient to power a SatNav as the power cable stretched across from the drivers door to the top of the dash. The switch under the dash by the steering wheel, to switch on the dash instrument lights was really superfluous as I preferred them to be permanently illuminated when driving at night. A waterproof socket (as advertised on eBay) is a similar size to the original switch and only required a minimum amount of filing to fit. This minor modification avoids having to butcher the dash and has proved a big improvement over the original set up.