The ability to install an iPod in a BMW has been around for a few months now and I hadn't given it much attention or thought until now.  Mainly because I now have a car that the technology supports.  So here's a mini review...

Installation: No idea if it's hard or easy, but it didn't take long for the dealer to do the work.  When it's complete there's a normal looking iPod cable in the glove box that disappears deep inside the car.  Other than that there's no indication that it's been installed. Once connected the iPod also gets charged, so after driving for a while you can take your iPod out fully charged.

The system is limited to playing five playlists on the iPod with a sixth option of playing everything.  You need to setup the playlists ahead of time and give them names that start with BMW1, BMW2 etc...  Easy enough to do, I created smart playlists to find all content that matched a certain genre, artist or was created in the last 60 days.  With those set up all I had to do to get everything to work was plug in the iPod.  The car believes the iPod is a CD changer and so changing to the right mode on the stereo starts the iPod playing.

Control: The iPod is controlled from the stereo controls in just the same way as that the radio and CD player work.  The preset buttons move between the playlists with just a brief pause for the iPod to find the right playlist.  Once it's playing it can be fully controlled from the controls on the steering wheel.

There are some limitations though.   Being limited to playlists is not a major problem, but if you want to listen to a specific album or song it could be difficult to get to it.  None of the details of the song are displayed either on the iPod or on the stereo when it's playing which may be a problem for some people.  For me, I almost never look at my iPod when it's playing anyway, so not being able to see the track info isn't a problem - it's a nice to have feature, but not a deal breaker.  A limitation introduced by BMW is that shuffle or random mode isn't remembered when changing playlists or when changing modes.  This appears to be a "feature" of the stereo system as a whole and isn't unique to the iPod.  Lastly I've noticed a slight background hiss, but I've yet to determine if that's from the files on the iPod itself (192kbs transcoded from lossless WMA9) or part of the system.  I can only hear it when changing tracks or during quiet parts of a track, but it needs more investigation before I know where the problem is.

Ultimately though, I really like it.  Having all my music available in the car is great compared to the six CDs I was used to that I rarely changed around.