The opening roof (5) comprises a panel (17) which can move between a closed position and an open position. A rigid windbreak body (22) can move perpendicularly to the roof (5) and is pushed outward by a leaf spring (33). Panel (17) acts together with an inclined upper wall (37) of the body (22) to allow the latter to move outwards when it moves towards the open position and to return it towards the interior when the panel (17) returns to the closed position. A pivot (38) for a rotating wall (39) which can open freely through the action of a torsion spring (41) is located on the top part (37) of the body (22). The rotating wall supports an additional windbreak member comprising a screen (42) equipped with microholes (43).