We just installed Sirius in our Truck. I also just leared that Sirius offeres digital HD TV via an add-on reciever. The tech forums say it's about the size of two packs of cigarretes.
We have the Kenwood 7100 Head Unit (navigation, Sirius, Bluetooth, DVD, CD, Ipod, MP3, USB, blah, blah, blah)...