How to add a photograph to a scene and render it realistically? I have basic knowledge of Blender, and I use it to render geometric primitives, such as a collection of cubes with different materials.

Now I have a scene with cubes and spheres on a plane (pretty basic) on which I'd like to put a "real object" of which I have a photograph only. This object is for instance a car. I don't have its 3D model, I can only cut it from the photograph.

I would like to incorporate that object in the Blender scene (for example: the car in front of the cube) and render it as realistic as possible. The object is photographed with the right perspective, i.e. from roughly the same angle as it is going to be put in the scene. I do not have big requirements such as reflections.

How can I do it? Is there a general approach?

I am aware of the fact that this is not really the conventional approach. I didn't try pasting the image on the rendered image in Photoshop, but I guess that won't really work.

For further information: I can take new photographs of the objects, and I have control over lighting.
Here I'm going to add this image of the Blender logo:


Once you get it rendering on a plane, modify the material in the node editor to something like this: