You won't get perspective or parallax shifts with flat images but if you can get 3D models you can first set a ground plane and origin from your Camera Track, then add a camera and a plane, then add a plane for each spot where a new building would be, then export your AE project and camera to a C4D project and position your 3D models where the planes are. Here's a very short silent demo:
I have asked the developer for a 3D model, but haven't heard back yet. If I can get a 3D model, I know how how to research it.
But assuming for the moment that I can't get a 3D model, and understanding about perspective and parallax, how would I go about doing this with a flat image?
Just add your solids as placeholders then add The image to the comp and make the layer 3-D. Now hold down the shift key and make the placeholder solid the parent of the 3-D image layer. Holding the shift key will snap the image layer to the exact same position as the solid. Then you just need to adjust rotation and scale. Then you delete the placeholder in the parenting will go away.
OK, I got that to work with your instructions. It doesn't look great, but it is definitely good enough, if I can't get a 3D model from the developer.
Thanks for your help!