I recently bought an Alpine KCA-420i iPod adapter from the local Best Buy and an Alpine 9825 CD player (as a closeout from Circuit City) to control it. I don't do a lot of driving during the week, but on weekends I often head up to the Great White North, eh? Radio reception gets pretty crappy between here and Vancouver, especially the NPR station that I know and love. And right now they're doing their spring fund drive, so the iPod feature has gotten a bit of extra use. The good news is that the KCA does what it says. The bad news is that the usability is crap, even if you haven't been spoiled by using an iPod. The reason for this is that the device is essentially a hack it makes the iPod look like a CD changer to the head unit, and since the iPod is not a CD changer, the usability suffers. Give a literate six-year-old an iPod (better get AppleCare!), and he'll probably figure out how to use it in short order. In fact the UI is so intuitive that the instruction manual that comes with the iPod is basically a waste of paper. I've got a hard-earned Bachelor of Science in Engineering and I couldn't figure out how to get the thing to work without reading the instructions (and let's just say that even if seven languages weren't included in the manual, it'd still be too thick to staple). By far the most infuriating bit is trying to scroll through a selection of songs, artists or albums. The scrolling is done through a little rotary encoder on the faceplate. But no matter how quickly you twist the thing, things scroll by at around 2 lines per second. There are three ways to "search" (read: scroll through at a 2 lines per second) for songs: all playlists, all artists, and all albums. The playlist "search" is more or less usable (more on that later). The other two search modes are strictly emergency-backup material: scrolling through a hundred artists at 2 lines per second while driving is an invitation to having a horrible accident. Same goes for albums. And both are made worse if some or all of your library is downloaded (legally or otherwise) rather than ripped from CD. When you go into an artist playlist, the songs come through in one big array, ordered by album and track number, so if you have a few hundred tracks by one artist, it's still a PITA. To their credit, Alpine acknowledges the above and recommends making all songs accessible through a playlist. I could do smart playlists by genre, but I'd end up with around four slightly less useless playlists ("Electronic," "Alternative" and "Rock," plus "Everything Else"). Instead I've decided to create eight (point one) playlists that are alpha by artist, then album, then track number (think telephone keypad). I'm not sure if this solves much, but I'll get back to you in about a week after I've had some time to try it out. In any case, there's a glaring business opportunity for some boutique car stereo manufacturer to improve on this. I picture a nice fat rotary encoder (maybe the force-feedback one I proposed on halfbakery.com), an FM tuner chip, a bitmap LCD display that doesn't suck (IOW, not like the 9825's), and an optional amp (since quite a few high-end audio types use discrete stuff nowadays). That and either an iPod dock on the front of the thing or a cable to run into the glovebox. The iPod remote protocol has been reverse engineered and in any case you could probably get it from Apple if you look like a perfectly legitimate enterprise. This is the sort of thing you could program a Gumstix to do. Why not leave out the iPod altogether? Well, first off you need a way to get the music from your (friend's) CDs or the internets onto your car stereo. Secondly, you can take your iPod with you (both to keep it from being stolen or to listen to music whereever you've driven to). Third so that you can buy from the largest online retailer of digital music and not have to commit a felony to listen to your music on the road. Another thought was why not "remanufacture" an iPod into a detachable-face-plate-like-thingy with more car-oriented controls? But in the end most people spend a fair amount of time listening to radio in their car, so unless you can come up with a good way of making an iPod control an FM tuner, I think it's a lousy idea.