Unfortunately I neglected to take very many pictures during the process. Sorry
Below is a copy and paste of my post on another forum describing the install;
Can't find the exact relay I used, I've had it for quite a while, but if you search for a remote control relay on ebay, you'll find a few.
Something like this; http://www.ebay.co.uk/itm/251185017251" onclick="window.open(this.href);return false; or this http://www.ebay.co.uk/itm/251167748518" onclick="window.open(this.href);return false; looks about right. The main point is that the relay should stay closed only while the button is pressed (i.e. not locking).
That needs to be powered off the car's 12v permanent power supply.
You can then connect the relay output to a door motor/solenoid, e.g. http://www.ebay.co.uk/itm/190320342026" onclick="window.open(this.href);return false;
Mount the solenoid somewhere under the bonnet.
Then get yourself a gear or brake cable from a bicycle (you want both the inner and outer cable) such as this; http://media.chainreactioncycles.com/is/image/ChainReactionCycles/prod47684_IMGSET?wid=500&hei=500" onclick="window.open(this.href);return false;
If you pop off the plastic trim around the charge ports (there are four plastic retaining pins), you can get access to the locking mechanism.
From there it's a relatively simple task to connect your bike cable to the lock (in the same manner the original release cable is attached) and run it back up to the solenoid.
Once you activate the solenoid, the cable gets pulled and the charge door unlocks. Simples
I really should have taken pictures, the above would probably make a lot more sense that way. Disclaimer: Do any of this at your own risk, I'm not responsible if you break you car etc....
