A motor vehicle door with a side-reinforcing bar

A motor vehicle door with a side-reinforcing bar which includes a frame (3), static connection means (20, 22) for fixing the bar (18) to the frame (3) when it is in an undeformed rest configuration, and dynamic connection means (27, 28) for fixing the bar (18) to the frame (3) when the bar is forced into an active configuration in which it is bent as a result of stress from outside the motor vehicle. The dynamic connection means (27, 28) for the bar (18) are independent of the static connection means (20, 22) and include engagement means (28) interposed between each end portion (18a, 18b) of the bar (18) and respective seats (27) in the frame (3), operable to secure the end portions (18a, 18b) of the bar (18) to the frame (3) should the bar (18) bend into its active configuration, thereby causing the bar (18) to generate traction on the frame (3) in correspondence with the said seats (27).