Could you explain how you do that with the multiple cars Chrome?
When you're setting up each car, try to imagine where the other(s) are going to be. Put your camera as close to the same place as possible when shooting each car. Once you get all the shots, take them to the photo editting program of your choosing. In my pic up there. I started with the pic that only had the orange car. "Cut" the pink and green ones out of their pics, and put them on the orange car's pic.
The main things to remember is...
Kept your camera in the same spot with the same setting for all the cars to be "grouped".
Allow enough room for each car. <----trickiest part
Mine got a little crowded, so I moved the pink car. It's off a little from where it should be, look at the bike in the window. The green car is spot on though. And it's the orange car's pic, so it has to be right.