YES. There are many ways from FM modulation (you tune your factory radio to a selected FM preset and the sound comes thru like an FM station) to adapting it directly into the radio.
NO. The manufacturer can’t void your warranty for changing your system. We at Freeman’s Stereo Video warranty our workmanship for as long as you own the vehicle.
A: Both have a wide variety in music to choose from but one of the main differences that people consider important is in the area of sports. XM has NASCAR, Major League Baseball, PGA Tour, ACC, Big Ten and PAC 10 football. Sirius has the NFL, NHL and NBA.