Hey everyone. I installed the GROM Ipod adapter
http://www.gromaudio.com/ipod.html in our 2008 5 last weekend. The install went pretty well except for a few changes to the interior pcs on the '08 that change the HU removal. Just remember to take you're time and remove the cup holders and console on the '08's otherwise, it's the same as on earlier models. Once you get the HU out you'll have to unplug the existing connection on the radio. The problem is once you do this, you lose the bluetooth capability, if you have it. I want to maintain the bluetooth compatibility with my phone, so I've disconnected the GROM unit until a Y adapter is made. GROM was talking about having one in MAY so hopefully it won't be long now.
The GROM unit was $70 on EBAY, displayed the tracks on the display, but no song name or titles, or playlists description. Playlist organization is important to ge the most out the GROM unit. Sound is great, charges the ipod, keeps it out of site and in the glove, and lets you use the steering wheel controls to change songs.