Here's an old Special Forces trick (no **** it really works and yes a Delta Force Soldier told me about it)....
Hold the remote to your chin and click it. It will extend the range of the remote.
Again ....this is a no **** thing that works. Walk backwards away from your car until clicking the remote won't chirp the car. Then put the remote to your chin and it will work. Back up even further and it'll work held to your chin and won't work if you just point it at your car. I've almost doubled the distance several times doing this. Works great at Lambeau Field....
Your body acts as a ground plane (google it) for the antennae in the key fob.
I've been in two of the factories that build those for the car makers. Believe it or not, the Koreans and some of the Japanese have their key fobs and assorted electronics (like the tire inflation monitors) built right here in the good old USA.