Despite economic woes and the general decline of radio’s relevance, Sirius XM radio, a subscription-based satellite-radio company that still plays out of cars (and/or on the Internet, but still for a price), actually added 583,000 net new subscribers last quarter, and expects to end the year with over one million new subscribers. Plus, over 46 percent of listeners who buy a car with a free trial subscription eventually sign up for paid subscriptions. Sirius’s headliner, Howard Stern, ends his run this December, but perhaps its increasing popularity could convince him to re-sign with the station. [Business Insider]