So, the picture you see in advertising with the tj style mirror attached is either a preproduction, photo shop, or ???. The doors you actually get will be slightly different and this is why the recommended mirror doesn't work. I was told to try leaving mirror loose, attach the door halfs...
Look at where the upper and lower meet in the advertisement pic, and mine. Advert pic meets near the base of the windshield, mine meets near the center of the cowl. Much lower. You can also see how close the top mirror mounting bolt is to the area where the upper and lower door meet. Sent some...
I'm going to give bestop a call first. I see product pictures of the twill with these mirrors mounted and it looks like the mirror base is below the velcro. Maybe the black diamond was built different or maybe the product pictures are a preproduction and they have a design flaw on their hands?
What sucks is I had to poke the holes for the mirrors to mount, so now I'm going to buy some bolts and washers to cover the holes since the mirrors can't be used.
You could but once you attach the mirror the upper couldn't be removed without removing the mirror first. Would be kind of annoying to have to do that everytime you wanted to switch between full and half door.