While there's no end of auxiliary input jack solutions for connecting any brand of MP3 player to a car stereo, most of the dedicated systems that show track playlists or charge batteries tend to be for the Apple iPod line. After-market systems that work with other players—such as the Harman Kardon Drive+Play II—are few and far between, not to mention expensive. It turns out that others are out there, though; as an example, Microsoft quietly released the Zune Car Pack for Zune fans, although a closer look at the specs proved disappointing.

The Zune Car Pack is really just an FM transmitter in disguise. For the uninitiated, FM transmitters let you listen to your portable MP3 player over your car stereo speakers without requiring a professional installation, and without even using wires. You plug your MP3 player into the transmitter and then plug the whole contraption into your car's DC outlet. The problem is that you have to tune the car stereo to an FM station—usually 88.3 or thereabouts—and then listen that way, meaning that you get all the static and restricted frequency response that comes with stereo FM listening.

The Zune Car Pack has some redeeming qualities, though. It actually charges your Zune, which is a big help on long car trips. It also has room for two FM presets, in case you get better reception at work than you do at home and want to switch during the morning commute. If it was up to me, though, I'd keep looking.