This is simply amazing! Looking at it more closely, I start thinking it looks somewhat like a car transporter of sorts. You could keep the rear fenders as they are but flatten the "bed" to accommodate on of your other vehicles - something like the W42, perhaps. I don't know the scales used and maybe you'd have to lengthen & widen the wheelbase but I think that would be something cool to see. Is it possible to combine two vehicles with the Apps you're using?
If you'll forgive me for saying so, it looks like it should have a trailer hitch on the back there. Other than that it I love the design. Again you never miss a chance to add a few extra curves or wrinkles in the bodywork.