iTunes doesn't burn mp3 dvd's, but you could probably hack a dvd to look like a cd. I would take a burned mp3 cd and look at it in terminal, see if theres anything there besides mp3's. something like ls -a /Volumes/mp3 cd name would get you a list of all the files, and you could just mess around with it. DVD's are a little expensive, but if you've got a superdrive money shouldn't be an issue
I know this thread is kinda old but the most important thing is whether your dvd player would even accept it. You can look up you dvd player at http://www.dvdrhelp.com (in the left column there is a button for dvd players) to see what capabilities it has. In this case you would be looking for "DVD-MP3, MP3 on DVDR/W support". I did a quick search and only 184 out of 2360 listed players claim support for DVD-MP3.