Hello @tallen and @ThirdEyeSamuel,
The way we do this is we create a separate TAG for each vehicle (could be the vehicle rego) on the device within InControl2. Anything installed in that vehicle (router, switch WAP, SDPMU) all have the same TAG. We may also use other TAGs related to the project and client needs.
We normally would create a unique VLAN first then a unique SSID for each of the devices using the related TAG to get the required SSID only on that device.
Another tool we use is a professional Wi-Fi spectrum analyser; this can show us the SSID, BSSID, MAC Address of the WAP, Signal strength of the WAP, signal frequency and signal bandwidth. Here is one such product from Metageek using the Chanalyzer software
Finally, you can also use the Peplink AirProbe range (many of the newer MAX routers can have this functionality turned on).
Happy to Help,
Marcus