This was the start of my test. Started around noon.
The trailer was in the direct sunlight, no shade at all.
Here's a pic of the vents on the inside of the trailer with the window template I made. No mods required to the trailer or the a/c unit at all.
You will notice the electric cord from the a/c unit coming in through the window. This is so I can plug the unit into my thermostat, and it will turn on and off based on whatever temp I have it set to, just like central air!
By the early evening, the trailer was down to 60 degrees, with the outside temp still in the low 80's.