question about mp3 audio

I know computers can play mp3, at various bit rates, mono and stereo, etc...

my question - are car stereos and home CD players that play mp3's limited to a certain type, bitrate, etc of mp3?

if, to save MB, I put a whole bunch of MONO mp3s on to a CDROM, will they play in most mp3-enabled car stereos, walkmans, etc? Or does it have to be 128/stereo to play in those?

reason - i'm working on a project to put a bunch of radio interviews relating to electronic voting on to a CDROM. My hope is people will be able to listen in their cars and walkmans, etc. I figure if I do it mono I can fit over 50 hours onto one CD. But if that makes it so it won't play, it's useless.



thanks
gary (the solar bus guy)

i'm no expert on this but here are a couple of links worth reading:

http://answers.google.com/answers/threadview?id=551151
http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/digitalmusic.html