Not saying you haven't, but ya'll should take the time to
#1 learn what military bases and facilities are around you- You should also try to know about the various things that go on there- units attached etc. (Sometimes small facilities might get A LOT of trafic because it''s where they do something as mundane as repainting vehicles.) This is something any prepper should be aware of.
#2 you should all spend some time recognizing bumper numbers and unit insignia. Every military vehicle should have bumper numbers that tell you what unit and major command a vehicle belongs to...
This link does a little explaining on the subject...
http://olive-drab.com/od_mvg_markings.phpAs an example
The left number tells us that this tamk is in the 4th infantry division, 3rd battalion 67th Armor Regiment. The right side tells us that it is in (reading left to right) Alpha Company, second platoon, 3rd vehicle
National Guard vehicles will have their state, example
North Carolina Army National Guard - 694 Motor Transport (cant make out the right side)