Sirius XM Radio (NASDAQ:SIRI) is rolling these days.

Shares of the satellite radio provider hit a new five-year high this morning.

Despite coming up short against Wall Street's top- and bottom-line expectations in yesterday's quarterly report, it's easy to see why investors are warming up to the top dog in premium radio.

Sirius XM revealed yesterday that it has repurchased $494 million worth of its stock this year. The $2 billion buyback authorization that it announced several months ago clearly wasn't lip service.

Despite the pesky presence of Pandora NYSE:P)

Sirius XM did jack up its free cash flow target for all of 2013 yesterday. The media giant now sees $915 million in free cash flow this year.

Strong auto sales this morning are only helping. Ford and General Motors checked in with April sales soaring 18% and 11%, respectively. When the country's two largest car manufacturers are posting double-digit percentage growth and more than two-thirds of those new cars are rolling into showrooms with pre-installed satellite receivers, it's a safe bet that subscriber growth will continue.

Jaded investors have seen this before. Sirius XM has retreated after smacking fresh highs. However, the fact that we're at the highest level in 62 months shows that bullish investors have eventually gotten their way following any pullbacks.

Sirius XM's valuation at this point isn't cheap, but it's also hard to value a content provider that owns or at least controls most of its programming.

Sirius XM has earned today's five-year high.