It is an M4 C2V, Command and Control vehicle. It is built on an M270 MLRS chasis. Based on side and bumper #s, the one pictured is one from 3ID during the invasion. 3rd Division had 3 of them. They were named Thor, Zeuss, and Apollo, or someting like that, Greek God names. Pretty nice vehicles. Only downside, driver can not get into the rear crew area without exiting the cab and walking to the back. Cab and crew area are totally separated by the engine behind the cab. More info here,
M4C2V.