I am about to finish up a few FWF details and needed to see what I had for space. I need to put the oil cooler and baffling someplace in there and also design the cooling baffles. Using the ghost images is almost like having x-ray vision!
Sam Hoskins showed me this trick (thanks Sam!). Using a tripod, take pictures of the plane with the cowl on and off in various positions. The camera cannot move between the cowl on and off pictures and its best to use a camera that has a timer on it so you are not bumping anything when the shutter fires. From there they were put into iMovie and cross dissolve transitions added between picts. Pretty easy. You will be able to find a more detailed description of the process in the next "To Fy" magazine available to Sport Aviation Association members.
Take a look at the video. Its quite useful to pause it during a transition. That is where you can really get a look at how things fit together.