Annys Shin writes: "... XM and Sirius are still betting that most of their customers will tune in when they're behind the wheel. The technology of satellite radio "is designed for vehicles," said Jim Collins, a Sirius spokesman who cites the same figures as analysts: There are 220 million cars on the road today and 16 million to 17 million new cars sold each year. ¶ By now, most of the major automakers are committed to offering one service or both, but it will be at least five years before automobile sales will be the primary source of new subscriptions, Helfstein said. XM now draws half its subscribers from the auto market and half from the retail market, said spokesman David Butler. Sirius draws more of its subscribers from the retail side, Collins said. ..." Link: Washington Post.