IJ, when you say you got "the kit" do you mean the add-on IPod interface that plugs into the back of the head unit, or did you just get an auxiliary input kit? If you got the IPod interface, how do you like it so far?
I went with the auxiliary input option back when my Rio Karma 20gb mp3 player still worked, and it was ok...great if you had a playlist already set up, but changing songs/finding songs while driving was a bit dangerous, and the fact that I couldn't charge it while driving without a separate adapter made it a less-than-ideal solution.
Once my Rio bit the dust I came very close to purchasing an IPod for the sole purpose of having more of my collection in the car, accessible through my head unit and an IPod interface add-on. The ability to interface a hdd-based mp3 player through the head unit is just sexy...despite how much some people hate the IPod, it is popular enough (or Steve Jobs has sold enough car audio execs on how "Insanely Great" the IPod is) that many of the car audio companies can justify developing IPod interfaces for their head units. It just sucks though that if you want that kind of controllability right now, you have to have an IPod.
However, several manufacturers are introducing head units this year with usb interfaces on them so you can just plug in a thumbdrive or a portable hdd...I'm almost glad my Kenwood mp3 cd player died on me now.
Anyways, didn't mean to hijack your thread IJ, just thought I'd throw some interesting car audio/mp3 info out there...