toad brake indicator gauge

[Beagle RC Air]

I am in the process of setting up Ready Brake (towbar/surge brake) on our 2009 Malibu. In the process of trying to find the toad stop light switch, it occured to me that some type of resistance switch (potentiometer or rheostat) along with the use of a small digital voltage readout might be a better way rather than just a light. So to the technicians on here who understand such things, do you have some ideas to offer up before I proceed. I would prefer to work with the negative side of the battery power and wire the plus side directly to the gauge or light, whichever I decide to use.

[Beagle RC Air]

Back to the top,,,
Not much interest in such an indicator apparently. We have towed about 300 miles with this setup. My preference is to keep things simple (KISS), but just a light on or off doesn't offer much.
Been advised on another forum that there is no way to 'screw it up'. That is really not the issue. I do care to have as much braking on the toad as possible without causing the rotors to overheat. Also, be nice to know on long downhill descents what is going on with toad brakes. (maybe remote temperature sensor)
In regards to the Ready Brute towbar, this is a really nice, well thought out tow system and from our limited use I would buy same unit.