I don't get around enough and this has probably already been posted but you were the second group of people I thought of when I saw this. It's not exactly the same but wow in a real way what a challenge.
DARPA ( Defense Advanced Research Projects Agency) has a $4M design contest running called the Fang Challenge to design with their open source 3d modeling tool the next Marine Amphibious Assault Vehicle.
Its available at vehicleforge . org
I know its not everyone's cup of tea but it stimulated me, I'm working on putting together
a team already to take a shot at this thing.
If this is in the wrong place please move.