A bit OT, but the protection on the sony CDs is not encryption. It's a data ring on the CD that takes advantage of the fact that PC CD-ROMs will read data tracks before audio tracks to force the PC to constantly loop through some bad data instead of playing the CD. While it's true that some encryption can be broken, on a system like a car where the manufacturer has absolute control over the quality and type of encryption as well as the IO of the system, it's pretty difficult and extremely time consuming to break it.
