We use an XM "Onyx" radio that's easy to transfer from our coach to our extra car when we're at our cottage. Each vehicle has its own XM antenna, and when the radio is in the coach, it connects to our Sony sound system using an auxiliary input. When it's in the car, it broadcasts an FM signal that the car radio picks up. Switching between the two is completely automatic. Our toad has a factory XM equipped radio, and we have XM's $9.95/mo "Mostly Music" plan for both radios.