Well, I wanted to overlay the air foil thingy over my car. I didn't take this picture but it is the same car. It looks like this guy took the pic at about wheel level. I'm guessing ideally you'd want the picture to be on the level of the windows / roof instead of the wheels.
One neat thing I noticed, it looks like my car's got just about the same angle as the ev1 going up past the rear wheels. Just on my car, underneath that bumper is pretty much hollow space.
Hey if anyone wants to redo this and knows they can do a better job, feel free to do it