Assuming that the antenna lead has a standard antenna plug on the end that goes into the factory head unit, you may be able to get a little better reception if you add an FM booster to the chain. I've never used one of these, so who knows how much good they are, but it's worth a shot. If not, you're only out $15 and a bit of effort.

crutchfield has one here:
http://www.crutchfield.com/S-nvHAO4P...sp?i=12044UA60