In my country, and I believe in most European countries, WiFi is standard.
As Jonno21 mentioned this is used for live traffic info, but also for live weather, actual fuel prices in your vicinity or whilst navigating.
Thus, on several trips abroad I was able to get weather info, fuel prices etc. along 900 km of navigating from Brussels (Belgium) to Toulouse (France); worked flawlessly.
Another feature is that, once your live traffic info knows of obstacles (works, accidents and so on) ahead, it offers you the possibility of taking an alternate route (you can choose between 5, 10 etc. minutes gain with regards to the original (obstacled) route; the MZD lets you accept the alternate route or not).
These services are, to my knowledge, not offered (or not anymore) in the US.
I understand that all CMU's have WiFi aboard (technically speaking) but that this feature has been disabled on the US versions.