[Folsom]

So I was going to put in a dog door for my mother and her new dog. Everyplace I went to in town looked at me funny when I said the slider was white plastic and glass... To me it seems like the most ordinary thing ever. I thought aluminum went out of style because of low R value? I don't know. It appears I'm from another planet.

Should I just use an aluminum one? Will it work? Should I order a vinyl one?

[Folsom]

Looks like I may have solved my issue, as soon as I stopped looking at conventional sotres http://vinyldogdoors.com/index.php

[ArthurDent]

I've dealt with these folks for 30+ years. Two doors in that period, plus some replacement weatherstrip. I still have the original as a backup, but mine were installed in a wall. Pet Doors out of Florida.  https://www.dogdoors.com/   Been some time since I needed them, but they were great folks to work with back then.

[Tubeburner]

The vinyl dog doors that add to the patio door are nice and look like part of the door. If you are in the Seattle area, I have one for a small dog I removed recently.