The I-pod hooks into the AUX jack. I currently am using a different MP3 player as well. The PAL I believe is to intigrate the I pod better with the stereo. Right now you must control the i-pod on the i-pod. I believe the PAL is in part to allow you to change songs etc via the stereo and steering wheel controls.
Not only that Keith, but more importantly the sound level/qualitly should improve with the PAL as well. Several folks have posted that when they use the AUX port, they have to put their IPOD volume up to the max and have their car stereo up pretty loud too to get a decent volume setting. The PAL is a true "line in".
Sorry about that. The one I have didn't come with a cassette adapter. It just has a standard 1/8" (3.5mm) cable that connects directly to the AUX input on the radio. The runs from the base of the Flex Tune and not from the iPods audio output. This gives you a line level output that is then managed by your radio. No need or option to adjust the volume from the iPod. The Flex Tune includes a Hi-Lo switch which I normally keep at hi. I find that at that setting it matches the volume level for the other radio sources (i.e. Radio, CD, XM).