Car body boosts WIFI signal

I'm receiving a WIFI signal from about 0.2 miles away from my car. If I point my receiver antenna perpendicular to the direction of the source, I only get about 150 kb/s download. But if I point the antenna at the side of my car, I get 600 kb/s.

The reflective surface of the car serves an an satellite dish to focus a wider area of WIFI signal towards the receiver. Instead of the antenna itself receiving a thin width of signal directly from the source, the antenna gets a much stronger signal by bouncing towards it a large area of signal that the car is exposed to.

The focal point is rather small and can be easily obstructed. If I put the antenna in front of my car's side view mirror and stand to the side, I create a focal point at the antenna and the signal is a strong 400 kb/s. When I stand far away from the car, the signal drops to a weak 100kb/s. Even though I am not highly reflective, my body is helping to focus the WIFI towards the antenna.

Yesterday, there was a metal trailer parked to the side of my car. When I hung my receiver antenna out the car window, I discovered at just the right height and length I could get the WIFI speed to max out at 1 mb/s. I was surprised that despite the trailer possibly obstructing a line of sight to the source, I could get a very strong signal.

Turns out that the trailer was actually improving the WIFI signal, by reflecting waves in the same way a satellite dish does. Between the trailer and the body of my car, the waves focused at a small spot where the signal was unusually strong. Today the trailer is gone, and I park in the same location Even though I've tested the same receiver spot repeatedly, and I cannot reproduce that 1 mb/s speed. Without the reflective presence of the trailer, that sweet spot is gone.

So it really is a tricky art to finding the best orientation and positioning of a receiver antenna to pick up the best WIFI signal from a source far away. There are many objects in the way that may be absorbing and/or reflecting the signal that it is hard to know for certain where the best spot is.