Improvements relating to vehicle cabs having airflow deflectors on their roofs

A vehicle cab has an airflow deflector (9) pivotally mounted on it for movement between a lowered position and a raised position in which the deflector is inclined upwardly and rearwardly from a front upper portion of the cab, and the deflector has, or is associated with, side and rear walls which together with the deflector define a compartment above the cab when the defector is in a raised position, Access can be gained into the compartment from inside the cab. A bunk (11) can be provided in the compartment for a person to sleep in the compartment. Seats (3) in the cab have back rests (4) which fold down on to the seats, or can be removed, so that a bunk, which is stowed at the back of the seats when not in use, can also be erected in the cab over the seats. In one embodiment the deflector (9) is pivoted to a frame (8) mounted around the top of the cab, and the side and rear walls are provided by a cover (26) of flexible material which is secured to the deflector, frame and cab roof structure and folds in concertina fashion when the defector is lowered. In another embodiment the deflector is formed by an upper part of a pod mounted on the cab, the upper part being hinged to a lower part to enable the deflector to be pivoted between raised and lowered positions. The upper part may be raised at the front relative to the lower part to increase the capacity of the compartment formed by the interior of the pod.