SWR, versus TEMP
My system has no issues with the variance in the temperature. I have nothing to do with it exept adding the radio, with a "little help," and pluging them in.
Using the meter on the radio (gasp!) I always get a 1-1 reading, and the ANT. light rarely glows. I use the Factory installed antennas, which are directly mounted to the mirror, not necessarilly it's mount, which I noticed is grounded to the truck with a piece of copper wire on each mount.
For some reason, I am not allowed to participate in your poll, yet, I prefer the metal "L" brackets, because they are better suited for holding larger antennas and withstand tree strikes. They are necessary for the Ham Stick, as well.
Some drivers will insist on a screwdriver antenna for HF, which may require a more suitable mount, often bolted also to the mirror mounts. If you are going to use any amount of power, mount your antennas as high as you can on the MM and if they are as tall as my Ham Sticks, at least mount 20M and 40M on the passenger side, not to tilt too far out, so that it won't grap EVERY low tree limb, or the occasional low bridge! Mount the taller antennas from the bottom of the bracket, not the top. ( Some mirror mounts are NOT exactly perpandicular to the door, as you might imagine, and angle back a bit, so if you tilt the antenna forward, it WILL stick out away from the truck striking many curbside objects!)
Thank You for taking the time to read my response.
The Road Ranger