It can happen that your internal services are still reachable from externally, by calling the external IP and setting the Host header manually to sub.mylan.home, even if that were pointing to an internal address. Traefik would only compare the Host header. To secure this you might also add an IP filter for the internal host, but I‘m not sure whether that’d be secure enough.

Up to now, I believe, these systems were not first-party but built by the manufacturers of the infotainment systems. Now, Mercedes is taking this in-house to get it right and integrate it with the rest of the far more properly?

Luckily I’m born on 07/07/2007 — finally my superpower comes into play.

Just in case you haven’t heard about this potential root cause: https://superuser.com/questions/1406140/monitor-screen-that-blanks-due-to-static-electricity-in-my-chair