Just to add what Rob has said, I found this on the web.....
BREN GUN CARRIER (UNIVERSAL/WINDSOR) (DUXFORD)
The role envisaged for the Bren Gun carrier was as a fast, lightly armoured vehicle that would carry infantry across ground denied by small arms fire, affording them a protective taxi service to the battlefront. A further specific task was to transport the Bren Light Machine Gun and its team in a reconnaissance and intervention platoon setting within a front line Headquarters Company of an Infantry battalion. It was this task that produced the familiar name 'Bren Carrier' which was applied to the group of vehicles of similar design. The Bren Carrier soon became the name which the troops came to adopt when referring to this tracked armour type. Vehicles such as the Windsor T16 carrier of Canada and several others that were made by a variety of manufacturers across the Commonwealth and all exhibited minor differences. This group of tracked vehicles were known by the name Universal carriers in the British Army of WW2.
The hull of the Universal carrier was made from a simple steel plating, welded in a box pattern, with an engine compartment located at the centre of the vehicle. The driver sat toward the front and to the right. He was partnered by a gunner sat inline with him to his left. The gunner's sole job was to operate the weapon , either a Bren .303 LMG or .55 Boyes Anti-tank rifle, when required to defend the vehicle or protect the troops carried.
Interestingly, even though this vehicle had been designed to carry infantry into battle, it was impossible to issue orders or hear a conversation because of the volume of noise created by the radiator's cooling fan. The radiator was mounted between the front two crewmen! No intercom system was mounted on the vehicle to compensate for the noise levels. Rectangular stowage compartments behind the two front crewmen catered for the transport of either stores and ammunition, or fully equipped infantrymen. Over 40, 000 Universal carriers were built by Canadian, Australian, New Zealand and British manufacturers during the war.
Jeff