The air flow across the tarp causes the lift and result is flap. If you disrupt the airflow with a netting type material on top of the tarp there is no lift or flapping. I have an old soccer net I use just for this, works like magic.
No need to go through the access panel. Thief went under the tailgate handle to unlock it.
Which means anything under my topper is really not locked in. I have an XL, so my lights are not a target.
I might try to disconnect my handle and look for an electronic remote switch, like in hot rods.
I was working on adding some mesh in the lower opening, so I removed the plate/bracket.
Looks so good without it! I never put it back, and if "someone " would ask where it is... I'm not finished with the project yet. Wink, wink, nod, nod...if you know what I mean?
The truck has a system that does monitor the draw of the amps on a circuit. But if you add small LED, it should work. I spliced in brake light for my topper on the exact wire you speak of and it works. I do not have blind spot sensors.
One way to make sure you have the right wires, take out your left rear speaker and follow the wires from there. Or run the input wires from the speaker.
I will be watching for your mod ideas.
I really like the side doors with a short garage. And because I'm short I use the milk crate as a step to reach inside.