I was going nuts with these white drip lines. I'm a member on a detailing forum and was asking those guys on product recommendations for removing the mineral buildup. Pretty funny... but I was pointed back here for this solution.

Great Idea! I used a 1/8" bit.

I actually took my mirrors off to polish the doors with my Porter Cable 7424 and also to see what was inside the mirror. I took a pair of scissors and cut a small "V" in the bottom of gasket to ensure that the water would drain out.

 

cool deal im going to do this when im done washing it tonight.

 

Ha! Thanks! I drove bimmers for 12 years before going with my JK. They were all BLACK and if taken care of... look BEAUTIFUL! As a result, I have a cabinet (6' x 4') full of detailing stuff. These white mineral parallel drip lines were driving me crazy. I kept telling myself... "someday"... I have to take care of that. This solution (drilling the holes) and my past detailing experience have solved the problem.

I do have to keep telling myself though.... "Its a JEEP, not a BMW".

These were what my white mineral drip lines looked like before:

 

Evidently not the only one. Drilled out the mirrors last night and didn't find a drop of water. Then again I don't use car washes or high pressure hoses.

 

There is a small tiny tiny little dimple in the very bottom of the plastic mirror housing that must be their "design intent" to drain any trapped water. I noticed this when I had the mirrors off. There is also a thick gasket behind the mirror to keep water out of the 2 large holes that serve to bolt the mirrors to the doors.

Must be that in some (most) cases the gasket is sealing/trapping the water inside the mirror?

I was getting this "trapped" (continuously dripping water) by just washing with a hose. The water would actually still be drippingout of the mirrors the next day or 2.... very frustrating.

 

Just took the mirrors off my 2009 Rubicon and found a channel in the bottom of the mirror to allow water to drain. They were dry as a bone and it's been raining for the past couple of days. Looks like the problem has been taken care of for new jeep buyers.

 

My `09 has the notch but the gasket still blocked water from escapting. I cut the gasket and drilled the mirror.

 

I love this MOD.. works 100%

 

WOW!

Picked up my 09' Unlimited at the dealer and they washed it for me before I drove off.
Notices the white water stains dried up on the driver door when I got home.

Decided to do the mod.
Driver door only let out a bit of water.

****
Passenger door pissed out ALOT of water for about a minute leaving a puddle that ran under the jeep all the way down the other side of the truck since I was parked on a slope. It really was a lot of water that came out the passenger side!!!!

And yes the 09 has the notch but it's not enough to do anything being a small notch and the gasket in there. Drilling the hole is the way to go.

 

I have to do this