www.MyPodCarKit.com FAQ

According to an independent survey "Sixty percent of iPod users use the units [FM transmitters] in their vehicles, but they are not currently satisfied with the integration solutions available." FM modulators are notoriously low in fidelity and susceptible to station interference. iPod integration modules offer CD quality sound with no chance of interference via a hard-wired connection to your car stereo. They also allow constant charging, control of your iPod through your factory car stereo, its steering wheel controls and in most cases offer album/artist text display. No bulky FM transmitters in the way and a simple interface with your factory stereo makes iPod integration modules the top choice for the most discriminating connoisseur of fine music.

Your iPod or iPhone connects to either a universal or vehicle specific integration module with an included docking cable. The module then connects to one of the various available ports on the back of your factory stereo (such as the CD changer port) via the included connection cable.