Cargo Carrier M30.
The relation of the M30 to the 155mm GMC M12 is apparent; the M30 is essentially an M12 with the ordnance removed in favor of storage room in the back. (Picture from TM 9-751 155-mm Gun Motor Carriage M12 and Cargo Carrier M30.)
The drivers' doors are open on this vehicle. (Picture from TM 9-751 155-mm Gun Motor Carriage M12 and Cargo Carrier M30.)
The tail gate on the M30 can be contrasted with the spade mounted on the M12. (Picture from TM 9-751 155-mm Gun Motor Carriage M12 and Cargo Carrier M30.)
The AAMG ring mount can be seen here, along with further details of the rear compartment and tail gate. (Picture from TM 9-751 155-mm Gun Motor Carriage M12 and Cargo Carrier M30.)
The tail gate is lowered here, showing its stepped interior face and the stowage of 155mm ammunition in the rear compartment. (Picture from TM 9-751 155-mm Gun Motor Carriage M12 and Cargo Carrier M30.)
