A hidden storage system is incorporated in the bed of a vehicle without altering the bed's external appearance and the bed is provided with collapsible support beams. The storage system is located adjacent the wheel well sections of the bed, and uses hinges to open and close the fender/side panel of the bed. The collapsible support beams provide a support/safety mechanism if impacted from the side. Since the storage system does not alter the truck's external appearance, it reduces the attraction for theft. Also, since the storage area does not extend inwardly beyond the conventional wheel wells, the storage system leaves most of the truck bed free for use. The hidden storage system is incorporated into the bed by either an initial fabrication method or a conversion method using an existing bed.