The side mirrors have a nice hole inside of the housing that leads down into the arm that holds the mirror. Jeep did try to mold a drain hole into the bottom lip where it mounts against the body. They then put a nice foam rubber pad in between this and the body effectively sealing their own drain hole. While surfing one of the various Jeep form’s out there I saw a post about drilling a hole in the bottom of the mirror to drain the water out.
I took the first mirror apart to see how it looked inside but drilled the second mirror while it was on the vehicle.
Here is a picture of the nice hole in the bottom of the mirror. This is where the water goes to fill up the arm. Jeep did include a molded in drain hole at the very base of the mirror where it bolts to the body. They also put a piece of rubber to protect the paint on the door that effectively seals this drain hole.
Drill a 3/16” hole in the bottom of the mirror right before the hinge starts. I lined the hole up with where the molded plastic comes together. You can be a little off. The water will still flow out. By drilling the hole here you will not get the water spots down the side of your doors. I will see if this size hole clogs up with anything and possibly go up a little on the drill bit size.