Thanks for the complements on the Olds boxart. I'm very pleased with the see-through view of the Olds.
Growing up I always liked the double exposure shots (mostly Funny Cars) that graced the covers of Hot Rod Magazine back in the late '60s.
When I shot my '53 Studebaker custom for SAE (not the cover, but the inside shot with the article) back in '93 I went a step beyond a straight double exposure. I used a technique called "matting". I learned it twenty-five years ago when I was a student at the Art Center College of Design, and it was considered old school then. Matting was commonly used in the early days of motion picture film combine two scenes into one.
For the Stude, I put a matte (black card) between the camera and the model. The card had a small oval hole that allowed me to expose only the engine (with the flip front body work removed). Next I removed the matte card with the small hole, put the flip front end back on the model, put a black matte the same size and shape as the hole and in the same position as the hole and then exposed the film again. Keep in mind the camera is locked down on a tripod.
This is a lot of work and it took four tries to get things to line up or register, if I remember correctly.
Why bother? Well.... matting gives control of what ends up beings 'ghosted'.
If you look back at that shot, the the area around the grille and head lights are not ghosted but the hood is see-through to show the engine. A simple double exposure would have ghosted the entire front end of the body.
In the digital age with the Olds: lock the camera down - shoot the chassis with the body removed - shoot another shot with the body on the chassis - use Photoshop to put the 'body-on' image over the chassis image as a layer. Then erase and feather away sections of the body 'til it looks cool. In the Olds image you'll see that some sections of the body are solid, other sections are ghosted and some are completely clear.
Ain't technology great!