The only way to tell where a truck has been is thru the bumper #'s once it has been DRMO'ed/GL'ed/GSA'ed/gotten rid of by Uncle Sam. If a truck is still in Active service, at least in the Army, there are a few ways to track it thru it's Serial and Reggie #, but once the truck is gotten rid of, all the info that goes with it gets deleted..
As for WHERE to look for bumper #'s for ARMY trucks...
#1 plase to look on the FRONT: both sides of the front bumper on the ends
#1 plase to look on the back: rear bumperettes, then tailgate, then in the no mans land inbetween the tailagte and bumperettes.
Other good places to find paperwork is glove boxes, BII/OVM boxes, behind the seats, under them, in the battery box.. You'd be amazed where 2404's and 5988E's end up.
Sometimes you find info painted inside the cab, on the inside of the doors, on the underside of the hood..
Bumper #'s are all SUPPOSED to be standardized as per the TB, but local command policy often overrides that.
Often a Google search on the MAjor COMmand or Battalion will provide info on units, where they are/were/ ect and can give you a good starting point for the last unit it served with.
I had trucks in my unit (4FSB, 4ID) that were transferred from from the 502nd FSB, 2nd AD. When the 2AD got disbanded, it got reflagged as the 4ID... If you looked hard enough under the layers of paint, you could make out the old 2AD bumper #'s.