This open space will be covered by a panel on top of which the heater unit will be placed in the engine bay. Once this space is covered it is one of the most hidden and inaccessible spaces in the car. The funnel construction guides hot air from the heater downward to the driver's compartment, ending under the dashboard on both sides of the bulky part of the transmission tunnel. The edge of a similar funnel is visible at the bottom centre of the picture The ring on the right side of the photo is to hold the mounting for the gearbox (hangs down from this ring). Note the reinforcements on the other side of the panel behind that ring.