I am one of hundreds if not thousands of people who are using 3rd party apps to control my Tesla Powerwall or car, but really I want to set up my own automations and not rely on other apps.

Unfortunately Tesla have made it pretty hard to auth to the Telsa API's (Called Fleet) as it now requires you to store your public key on the same FQDN that you are using to make the OAuth calls to Tesla. This is something I cannot see how to do in Make.com ... I think an app like this spread like crazy in the Telsa community and be very successful.