Is it an actual connector on the other end (on the cab side)? Sure looks like it would be, but... My '05 just had the rubber accordion tubing between the door and cab.
.....Just did some searching and I think this will work fine for you:
How to wire through a door molex.
AFAIK, most "Molex" plugs use similar (if not exactly the same) pin styles, which are available online. If there are any open pin locations on the Molex connector itself, you may be able to just add the wires into the connector instead of drilling it.