They've had a system called RVTT (Reconfigurable Vehicle Tactical Trainer) that's pretty cool. You go in a little building or trailer, and inside is a HMMV, MRAP or MATV. Once the door is closed, you are surrounded 360 degrees by projector screens. There are individual weapons (m4s, m249) as well as a mounted crew served weapon in the vehicle turret. The simulation doesn't have the best graphics, but they're good enough, and driving the vehicle makes noise, and all the controls work as you would expect them to. If you jump out of the vehicle, your weapon tracks your player in the game world, showing you dismount the vehicle and move around (up to ~7m away from the vehicle.) You can connect up to 6 of these system together at one time, so that you can see the other vehicles and players while conducting a convoy operations mission. It can also be loaded with real world roads, terrain, buildings, etc.
It's a very cool system, which can provide some great convoy training for anyone of any experience level. Also if you have 6 vehicles, each with 5 occupants, and you set the weapons to unlimited ammo and crank the enemies way up, it's essentially the most awesome LAN party you've ever been to. I was shooting like 15 dudes off each overpass with the m240 as RPGs whizzed by all over the place.