[Antennas] OT improving range on A T and T tilt phone

[Mark]

Hi
     My sister is required to use the A T and T Tilt phone for her job. Since her job requires that she be on the road allot and the she is constantly running out of the A T and T cell phone range, what can she do to improve the range of the cell phone? I have heard of cell phone antennas for cars but I have no idea how to connect such an antenna to the phone. How does one find a good car cell phone antenna any way?
     Thank you for your ideas.

God bless,
Mark
Jesus Is Lord!
Pendleton Redeemer
http://pendletonepiscopal.org/