"Cash for Clunkers" has been a potentially short-lived winner for Sirius XM Radio (NASDAQ:SIRI), but the satellite-radio operator is moving beyond the new-car showroom.

In a deal with Audi announced this morning, SIRI will offer buyers of certified used cars an introductory three-month trial to Sirius' service. It announced a similar deal with BMW two weeks ago.

The move's a no-brainer for Sirius XM. If the used car has a satellite receiver -- something that becomes less likely, the older the vehicle -- everyone loses if it becomes a dormant in-dash paperweight.

Ideally, the buyer would notice the receiver and contact Sirius to inquire about its activation directly, but why chance it? Motivating a used-car salesperson with a financial incentive to promote satellite radio makes the hands-on education process a breeze. The margins won't be the same as leaning on leads, but Sirius XM can make up the difference in volume.

Besides, satellite radio could use the new revenue streams. Retail subscriptions have been shrinking for several quarters. Things have been rolling better at the dealership level, but Sirius XM suffered its first sequential dip there during the first quarter.

Until new-car sales bounce back, Sirius XM is devoting its marketing efforts to promoting its digital-streaming service through Apple's (NASDAQ:AAP) App Store. Just as RealNetworks (NASDAQ:NFLX) brokered a deal with TiVo (NASDAQ:TIVO) to offer its Rhapsody music subscription through digital video recorders, it would be a shock if Sirius XM doesn't find new partners beyond Apple to serve up its Web-served programming.

One can also expect more deals with sellers of certified used cars, as well as with used-car specialists such as CarMax (NYSE:KMX), in the future. If there's a dormant receiver out there on the open road, Sirius XM wants it activated.

More news than static on Sirius XM:

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Longtime Fool contributor Rick Munarriz subscribes to both XM and Sirius. He owns shares of TiVo and is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.