Yesterday my car went in for a service, so I took the opportunity to get the iPod interface installed. It works just as advertised, with the 5 playlists named BMW[1-5].* showing up effectively as CDs and pausing when the car is switched off just like a regular CD player.
I had been using an FM transmitter, but there is no single station that I can tune it too that works for my entire journey to work - I'm forever changing the frequency on the trasmitter and the car. And that is just plain dangerous. Plus is sounds awful with all the bleedthough from other stations.
It would have been nice to get one of the cool third party solutions that adds a head unit that displays tag information, but I really didn't want a new head unit that looks out of place. So I just went for the first party solution.
My only niggle now is that my music library is at home, and I sync it every night (with iPodder downloading the new podcasts). I use firewire there. At work and on the road, I can't change the playlists or download new content using iTunes on my laptop, because as far as I can figure out only one instance of iTunes can work with the iPod. I can't mess with the playlists from my laptop. This is very annoying as I'll be at a conference in a couple of weeks and want to download new podcasts to the iPod while I'm there.
So yesterday I tried ephPod with the iPod connected to my laptop via USB. This allowed me to edit playlists and create news ones, but as soon as I docked the iPod when I got back home, iTunes decided to re-download my entire music library because the iPod was "suspect"! That took ages (20 GB of music).