I am trying to install a sirius radio in a 2001 Mercury Sable that has a cd player and radio. Any tips?

The problem that I am having is that the wireless connection method is no good if you travel long distances (700 Miles). The fm channel that you need to select keeps changing. The radio I have does not have input jacks for satelite radio. It does not have a cette player so I can not use a cette adapter. Is there any type of CD apapter for satelite radio? Does anyone have any ideas. I do not want to buy another radio.