I don't see the boot you are talking about. Under the glove box, there are wires coming in from the engine compartment, but they go downwards and I can't see where they come out on the other side. I'd still have to drill.
Right now I've ghetto-rigged my power cable by running it under the hood and then through the door. You can't see it when everything is closed, but yesterday I discovered that it creates a slight leak. So now I have to drill after all.