How can I increase range on the key fob?

I think the short range is intentional, to protect you from thieves who can use your own fob to steal your car while you're nearby:
Could you get "carhacked"? The growing risk of keyless vehicle thefts and how to protect yourself - CBS News

 

Touch it to the underside of of your chin and press the button.

 

Hold the fob high in the air with your left hand, lift your right foot and spin counter clock wise.
Works every time

 

What ColoradoCrow said is what works.

 

I don't like having a keyfob with 1993 type range. But I guess it's all for the best with all the kid hackers using it to steal cars.