Let me start by saying that I don't like the big metal washer on my dash. I am looking for a slightly smaller washer and a black or gray boot of some sort that would slip over the top of the washer and around the stem of the uniball to clean up the look.
For now it is very functional, my install just doesn't look good...yet.
I drilled through the thicker gray part of the dash because I thought it would give better support. The black dash can be more easily replaced but it is thinner plastic. If I ever changed my mind I can just add a flat gray "plug" to cover the hole.
with the stem loosened and moved out of the way so you can see how it attaches. I could also add a double ended stem to the ball mount and have 2 phones or a phone and tablet on the same mount. There are a TON of options for these mounts. The bigger ball mounts will hold like 50# or so. Check out the website.
I notched the black center dash for the head units rear USB cable and bluetooth microphone wires to come through. I wanted minimal wiring to be seen. I left slack behind the dash that can be pulled through in case my dogs snag a wire horsing around inside.