re: :( See, you gotta use the EXTRA thick foil....
Here's something related that I saw on BBC's 'Top Gear' a couple of years ago
If you have remote central locking - keep clicking it while you step away from your car - keep walking till it stops working.
Then point the remote at your forehead, and try again....and you get almost twice the range.
Lots of reasons have been suggested, my favorite is that the back of the skull acts like a parabolic dish - directing the signal back toward the car.
And I bet tin-foil-hat-wearing would make it even better :)
Doug