Rumors have the ring of truth for a reason: Sometimes, they’re true. Such is the case with the satellite iPod, which seems to be on target after all.

Apple has filed a patent application for a protocol set to save media for later purchase. Specifically, satellite radio is mentioned, as in an iPod integrated in your car able to buy a song that comes on your favorite XM station. That’s the most popular scenario, it seems. The patent also mentions other forms of wireless signals, including AM/FM radio and Wi-Fi.

That wireless “finding” thing… isn’t that one of Zune’s selling points? Which came first? Which will be more successful? Care to harbor a guess?