Of course, it doesn't actually look invisible unless you're standing in exactly the right place. That is why the stationary shots at the beginning of the video look so much more "invisible" than the moving shots later in the video. If you pause on those later shots, you'll see that there are big discontinuities around the boundary of the car.

Thought experiment: imagine the car as a sheet of glass. Think of yourself standing at position A and looking at a point X on the glass. You see a position A' behind the glass. Now imagine moving to a position B and looking at the same point X on the glass. You see a different position B'. The LEDs don't know if you are at position A or B, so they can't know whether to show the light from A' or B'.