Playing MPEG4 Video

[ryX5]

Has anyone had any luck encoding and playing a DVD with MPEG4 (or any other video format) with the DVD changer or the rear entertainment system?
Tried encoding MP4's using differnet compression settings but the disk is only recognized as CD and the files only play the audio with no video showing (both on the DVD changer and in the back)
The files all play fine on the PC directly from the DVD.

Regular DVD's play fine of coarse but I would like to be able to encode a bunch of kids videos on to a single DVD so I don't need to switch DVD's for the kids every time...

Any ideas?
Ronnie