Well, you don't need them to tell you that. It's enough to open any car to know that. And this term is actually not used for such a soft guarantee. In X-Plane for instance, which guarantees backwards compatibility when your plane used to work and doesn't work on a new version it's treated as a bug. If something used to work and uses documented API/features has to continue working in a new version unless otherwise mentioned. That's what worries me. And where do you see them saying that? Because I can see them saying something exactly opposite in the changelog. The fact that it's not true is the reason I have an issue with that. If they did say that this is how it is. New sound engine, you need to update the cars at least they would be honest. The didn't say that.