Note. Tesla can't support captive portals, so if any Wifi you connect you requires some level of authentication via a captive portal web page, then you're SOL.
I can't seem to find a reference to a thread in which the option is discussed, but I recall reading of people who get around this by jumping through some hoops. From memory:
- Ensure the Tesla is not connected to the WiFi network you want to use; even an unauthenticated connection will cause problems.
- Use a MAC address spoofing procedure on a tablet or cell phone to give that device the MAC address that your Tesla normally uses for WiFi. Apparently this is easier with Android than with iOS.
- Log in using the tablet or cell phone.
- Turn off WiFi on the tablet or cell phone. Be sure WiFi is completely disabled, or there will be a conflict.
- Connect with the Tesla.
- When you're done, un-spoof the Mac address on your tablet or phone, so as to prevent conflicts in the future.
The idea is that the public WiFi portal will authenticate the table or cell phone and then, when it disconnects and the Tesla connects with the same MAC address, the public portal won't require re-authentication, since it believes the Tesla has already been authenticated. I can't promise this will work, but it's at least cheap to try.
One major caveat is that you need the car's WiFi MAC address. I don't know of a way to find this from within the Tesla's UI. You can usually extract the MAC address from a WiFi router, including a tablet or cell phone when you activate its WiFi hot-spot feature, but details differ from one WiFi router to another. Thus, you may need to do some sleuthing to find this information.
In searching for a thread that covers the preceding procedure, I stumbled across mention of travel VPN routers, like
this one. I've never used one, but apparently they can be used to connect to public WiFi networks. They then create a second WiFi network to which your car can connect. The main point seems to be to increase security, by making it harder for other users of the public WiFi network to snoop on your data or break into your devices. You may need to use your tablet or phone to connect to the second network so as to authenticate before the car will be able to use the connection. The device to which I've just linked is only $30, so if you needed to use such networks regularly to update your Tesla's firmware, that's probably be a reasonable price to pay, compared to doing the MAC address spoofing dance every time. As I say, I've never used one of these devices, so I can't promise one would work for you. (The link above was provided in
another thread on this forum.)