This started out as just a test with Zbrush, using noise and greebles to generate detail. I then passed the objects to Keyshot, duplicated the buildings, downloaded a nice old Citroen van and some 3D people, which I posed with Mixamo and rendered a normal, depth, AO, and clown pass.
I then messed about in Photoshop for a bit.
The whole thing took about 3 hours, which was the goal of the exercise: to see if I could use this workflow effectively in a work situation.
The answer is yes ;)