The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.

NEW YORK (

Trefis

) --

Sirius XM

(SIRI) - Get Report

is going to report its third-quarter 2011 earnings next week.

Despite the state of the economy, we expect the company's growth to continue. To understand what to expect in the upcoming release, we need to understand what defines Sirius XM's business. The company has ties with automotive manufacturers such as

Ford

(F) - Get Report

,

GM

(GM) - Get Report

and

Toyota

(TM) - Get Report

, and installs its radio equipment in automobiles.

While the automobile subscribers are not the only source of revenue, they are by far the prime focus of the company. The retail subscription base has been coming down. Therefore, automobile sales, which are tied to state of economy, are the biggest factor in determining Sirius XM's financial results.

Our

price estimate for Sirius XM stands at $2.18

, implying a premium of more than 20% to the market price.

See our full analysis for Sirius

here .

Despite weak economic growth, automobile sales haven't done badly and that bodes well for Sirius XM.

September sales

were good, and the overall outlook for the year looks pretty good given how the economy and stocks have performed.

Even if sales remain flattish as predicted by

Automotive-Compass

, the increased penetration in cars will allow Sirius XM to grow.

Therefore we expect continued subscriber gains this quarter and maintain our healthy 15% overall subscriber growth expectations for the whole year as of now. Investors should stay tuned for growth in automotive segment and outlook for remaining year, and for 2012, that the company might provide during its earnings release.

Sirius XM is not just relying on new vehicle sales, but also making use of used vehicles to expand its base.

This commentary comes from an independent investor or market observer as part of TheStreet guest contributor program. The views expressed are those of the author and do not necessarily represent the views of TheStreet or its management.