Sirius XM Radio (NASDAQ: SIRI) said that 715,000 new subscribers were added in the second quarter, bringing its total subscribers to a whopping 25 million.

The company reports that strong automotive sales helped increase its net additions by 15 percent over the second quarter of 2012, which sets a post-merger record for quarterly net subscriber growth.

Also, the company expects to finish the year with 1.5 million new subscribers, an addition of 100,000 from the previous forecast.

"The new subscriber additions in the quarter have helped SiriusXM reach an exciting new milestone that reflects the popularity and reach of SiriusXM programming and services," said Jim Meyer, CEO, SiriusXM.

Myer continues: "The quarterly results bolster SiriusXM's leadership position in a dynamic audio entertainment marketplace as we continue our trend of strong, profitable growth."

The existing 2013 guidance of 1.6 million self-pay net subscriber additions remains in tact, noted Myer.

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