It starts with shooting the background after much thought and planning goes into how the specific vehicle will look in my shot.
When I have a background image I think will work, I'll then set up a different camera where the car would be and shoot a panoramic image of the surroundings. This records everything that's going be reflected in the car.
The next steps involve setting up the 3D data of the car and placing it in the right position in my background image.
Finally, the 3D data and the panoramic image are used to calculate all the lighting and reflections to generate a realistic image. With a little color adjustment and retouching we get the final image below.