#13 I've seen done by putting it under your chin and opening your mouth some. The guy proved it by pressing the button a bunch of times far away without it working. He then put it under his chin and opened his mouth and pressed the button again a few times and the alarm kept switching on and off then at the same distance.
If you're tight on space in your garage, measure the position of your windshield when your car is in the right spot, and then hang a tennis ball from the ceiling so you know where to stop.
#13 I've seen done by putting it under your chin and opening your mouth some. The guy proved it by pressing the button a bunch of times far away without it working. He then put it under his chin and opened his mouth and pressed the button again a few times and the alarm kept switching on and off then at the same distance.