I recently purchased the Boss Audio DVDC9000 6-Disc DVD Changer for USD $235 from Buy.com (US shipping only I think). This is a stand-alone changer that has two composite video outputs, line-level stereo outputs and also an optical SPD/IF connector for input into a surround processor.
So far I have found that it plays MP3's from both CD-R and DVD-R (with a hitch). The problem with playing DVD-R's is that the player often throws a fit on power up when trying to recognize a DVD-R disc. When it does decide to accept the disc, some songs play fine, while others tend to skip. I have found no such skipping problems with playing MP3's off of CD-R discs.
It may just be that I haven't found the best blank media to use in the unit yet, or maybe I need to get a different DVD burner. I have an early model DVD burner, the Pioneer DVR-A03, so it may be time for a replacement. I have tried using Mitsubishi/Verbatim 2X DVD-R media and a generic brand.
My other complaints with the unit are as follows:
The skip track Next and Prev buttons are the up/down buttons. When playing a CD-Audio or DVD disc, up is Next and down is Prev. When playing an MP3 disc, this is opposite.
When you turn the car off and back on again, it will resume playing a CD-Audio or DVD movie from where it left off. For MP3 discs, it just displays a list of folders/files when you start the car. You then have to navigate through the files/folders to the songs you want to play.
The default volume for the line-out jacks on the unit overdrives the input on my R33 factory LCD TV head unit and causes a lot of distortion with some music. This can be fixed by using the remote control of the DVD changer to turn down the volume output (from "15" to "5" or so). Unfortunately, this volume setting reverts back to max when the car is started.
For playing DVD video discs, the unit does an excellent job. I have had no problems with the player so far in this department. It even plays VCD's/SVCD's well.
If DVD, VCD/SVCD, or CD Audio is your thing, it is worth a look. On the other hand, I would stay away from this model if you intend to primarily play MP3's. I would instead go with something like a 10 or 12 disc CD based MP3 changer until prices on the brand name DVD units come down to reasonable levels.
Edit: Ahh. Forgot to mention that the player above is a region 1 DVD player, I'm not sure if there is a multi-region selectable feature on it or not. I am also not sure if the composite output is switchable to PAL or not, as I use NTSC.