The bed factory in Paramount was only for Toyota IIRC. The reason for its existence was to exploit a loophole in tariff laws that Detroit lobbied for to keep Japan out of the U.S. pick-up truck market. To avoid paying the high tariff on imported pick-ups, Toyota built this plant to manufacture the truck beds while the trucks themselves, sans beds, were built in Japan and shipped here with a bare frame for the bed to be installed on later. These trucks without beds were not classified as pick-up trucks and thus avoided the high tariff levied on imported pick-ups.

I picked up, spotted, and moved a lot of these cars around years ago when I worked for the UP but I never took a photo of one.