Own one of each vehicle available in the game.
Now, how exactly do you go about getting this achievement? Do you have to own one of every available vehicle at once in a single map, have owned one of every available vehicle at some point during a single map, or just to have owned every available vehicle at some point during any map?
I've started a scenario in 1920 Berlin with the hope to owning one of every vehicle at the same time, but I'd much rather know if I don't have to go to such lengths, rather I just need to have owned every vehicle at some point. Especially when some of the vehicles are vastly inferior to others around the same timeframe...