(Reuters) – Sirius XM Radio Inc said Tuesday that the number of people paying for its radio service rose to 25 million in the second quarter, helped by strong auto sales, and it raised its subscriber expectations for the year. Jim Meyer, chief executive officer of Sirius, said the 715,000 net new subscriber additions in the second quarter, up 15 percent, set a record since the 2008 merger of Sirius and XM. For the year, Sirius increased its forecast of net subscriber additions by 100,000 to 1.5 million. …