Just like 3 weeks ago I started using Tailscale. I’d highly recommend trying that.

It does some uuuuh… magic to establish direct connections on most networks. You can verify whether you’re using direct connection or relay using tailscale status on Linux.

It uses Wireguard under the hood. There’s also Tailnet lock feature (still in beta) in case you don’t trust Tailscale to not maliciously add devices to your Tailnet.

This would give you lower latency than the VPS solution. I use it with CG-NAT on both sides. I also started using it for LAN since it establishes direct connection over LAN too, and seamlessly switches between networks so I can disconnect from LAN and keep current connections going over WAN or vice versa.

But I’ve just tried now, and it won’t work even on LAN without internet access. Still better than a VPS solution in some way.

But you may also try looking into headscale which is basically a lightweight self-hosted private Tailscale control server, but I haven’t tried anything with that.

Not sure if you’ll find something that cheap, but RackNerd has some pretty cheap offers sometimes. Thing is, they don’t seem to expire, so there’s this: https://racknerdtracker.com/?sort=price

But I haven’t tried them yet.
Also keep in mind the monthly bandwidth limits.
You get what you pay for, and $10/year is basically nothing.

Oh, and you may be responsible for random people’s traffic depending on the provider. I think I’ve read in ToS of some VPS provider that you have to notify them about running a public service for this reason.

I sometimes get this with Mullvad in official YouTube app as well.

Or streamed directly to your device, only relayed through Tesla’s servers if necessary. This wouldn’t need much bandwidth as most connections could be directly peer-to-peer.

You know, I am just thinking of something like Tailscale or WebRTC. Though this would need a 24/7 connected app, so probably not the best solution.
Though if it were used just for the video streams that would likely help a lot too.

Or maybe release some server software that you could self-host and set up the custom one in the car. That would also have the advantage of being independent and future-proof.

Would probably be OK to include in the car costs. You know, like smartphone updates. You don’t pay a monthly fee for those either.

Edit: As for car’s connectivity, it could just have a modem with user-replaceable SIM card and/or eSIM. If the current ones can’t do that, add drivers for some USB modems and USB Ethernet adapters.