Technical Sirius Question

I have a Stiletto 100 portable unit that I also have a dock for in my Jeep. I had to buy a replacement dock for my Stiletto as the old one was installed in another vehicle that was sold. Since I had Future Shop professionally install the dock for use, with the FM transmitter, I have problems with other vehicles' FM broadcasts over riding mine. In my old vehicle I didn't have this problem. Is there any way I can improve the FM signal strength of the dock?

I realize that I could play with the setting and find a frequency less used by other motorists, but that doesn't fix the problem. It simply avoids the problem and inevitably I will run across vehicles that are set on that frequency and the problem will reoccur.

The only solution, as dumb as it seems, so far is to put my hand near the dock. If I do that the signal improves, seems crazy but it works.