So, you want to run a cable either from inside the car to the outside or from the outside to the inside.

The main wiring harness goes through the bulkhead near the middle. There's no good access on either side.
So we need to look for an alternative. Thankfully there are 2 that are perfect for both LHD and RHD users.

I have removed the bonnet panel but I have also removed the headlight. You don't have to do that.
My headlights were out at the time but it made it easier to take photos.

Passenger Side For RHD

Look at the top of the suspension strut. Now look up a bit...



...and you'll see a black plastic grommet.