I know the dev team just wrapped up their revamp of the D Series trucks but I feel like a few small things are missing. The first items are bed accessories. Starting with a drop-in bed liner. I can't imagine it would be a terribly hard thing to add, but it would really add that last extra bit to the 90s era truck. I also wouldn't complain if the toolboxes were redesigned to fit across the width of the bed, near the cab like most work trucks. I know this last item is a bigger ask, but a slide-in camper would be cool for a moderate off-road config. The bigger project would be some sort of unibody, Avalanche, like truck. It would probably work best with the Crew Cab Truck frame. The cab and bed would become one piece, with some sort of buttress coming off the back of the rear door frames. The back cab wall could be animated such that it folds in like the "Mid-Gate" on the Avalanche.
I was just thinking to myself earlier that the D-Series could use a bedliner! Also, the camper would be cool too.
There's already a dedicated thread for the Gavril D15 that you could use instead of making a new thread. There actually is an unused bedliner already in the game's files. More miscelaneous accessories certainly would be cool though. As for a unibody on a frame SUV/Truck approximately the size of a short bed crew cab, you just described the Kentarch D-30 with the third row seating and carpet removed I'm not really sure of a way to get a different one in the lineup that would make sense... I guess a pickup Roamer as an upscale semi-luxury alternative to the D15 could work for that.
as much as i hate super short beds I think a 5 foot bed crew cab truck on a ext frame would be pretty cool