I have to admit it sounds tempting. The range on my car key remote is very short, I have to be within about 10 feet of the car to do anything. So there are times when I walk away and forget if I've locked it, or times after a long day when I can't quite remember where I parked. According to the video above, and to the comments confirming it, you can extend the range of the signal by holding it against your body to increase the antenna. The video says you have to use your head but people in the comments say holding it against your hip works fine as well.
If it really does work, that's pretty cool.