After a few hours of poking and prodding it turns out that there is only one place that you can get a cable from inside to outside, and that is through the grommet that takes the bonnet release cable

This can be found in the middle just above the carpet line of the passenger foot well, There is also the main loom grommet just to the left and up from this, but this is no good as the wires are rubber sealed into the grommet.
Now pushing the cable through was not so easy as the hole is a super tight fit around the bonnet release cable, so I had to start with some stiff 12 Gauge wire,
One thing to note at this point is that Fairy Liquid is your best friend and you will get nowhere without it.Once you get the wire started I found the only way to push the cable through was with long nose pliers, you cannot really pull the wire through as it comes out, down and below the battery, and you will be pulling the wire at a 90° angle,which is a bit risky.
Once it was through I then taped it to the 8 Gauge power cable

Now as long as you use plenty of Fairy on the cable you should be fine, The 8 Gauge went through a lot easier than I thought it would

And there you have it, there is a nice channel under the door rubber as shown in the picture above, so running the power and phono cable was relatively easy with the only sign of any cables was when they came out around the rear seatbelt anchor point.
The image below is were I bought out the cables, the plastic cover is easy to remove if you start at the opposite end to this picture and pull it straight up, were it will just unclip, there is a fair bit of room under this to keep all your excess cable as well.