Cable hookup for rear-view mirror replacement?

We're installing a new rear-view mirror on the driver-side door of a 2011 Prius.

On the inside forward end of the door, there's a triangular panel that peels off, exposing the mount points for three bolts that hold the mirror on:



There's an electrical cable about 16 inches long coming off the mirror that's used for the controls to move the mirror up-down and right-left from the inside of the car. This feeds down into a hole -- but without prying anything else off, we can't see exactly where it goes. We need to get there in order to plug the new cable in.



So: What do we need to do next? Does the inside door panel have to get pried off? Or is there some other way to do this?

 

For what it's worth, we figured it out with the Haynes manual. Unless you want to splice in the new mirror's electrical cable where it's exposed, you do need to remove the door panel.

 

Agreed, and that's what we did.