Just got a 60 gig Video Ipod and researched the best car integration. Hands down it was hard wiring. I went with the Periperal kit for Euro cars from Best Buy. It was $199. I also saw them on ebay for $159, but I wanted to be able to return it if I didn't like it.
The installation was simple. There are little dip switches that you have to align, this takes 5 seconds. Then unplug the CD changer cord connector in the trunk and plug in the Peripheral interface. Then run the cord to the front of the car, stealth or not, your choice. Then attach the included i pod mount which has several options. I mounted it to the left vent, it snaps right in pale and is the perfect location for viewing and adjusting.
Now I can watch videos [not while driving :)] And I have access to my entire music library.
Hope this helps somebody.