I keep thinking about picking up a DICE, but since I have a 2005 car that will play MP3 discs, I'll probably just save my money.
One of the better stock audio system setups I've seen in a car of this class is in my brother's 2007 A4 (B7), which has an in-dash six disc CD changer that will play MP3s right off the disc. Not only this, but it has a large display screen that will read out the name of the song and allow you to cycle through album name, artist name etc, and a full featured menu system that will let you browse the disc as such.
The BMW headunit, for the sake of comparison, will still allow you to select songs by folder/album (it works the same way the CD changer does, where the first number is the folder/album instead of the disc and the second is the track number), but it won't show the name of the folder or the tracks that it's playing.
No significant quantities of judgment-impairing narcotics were consumed during or before the creation of this message.