Does anyone know how to create a cd that will work in a car or regular stereo using a CD-RW??

If I'm not wrong, some of the older car stereos and CD players just won't play cd-rw's. The latest ones should play them no prob. I'm sure someone will post with more info than that tho.
Steeve.

Creating an Audio CD is the same process for CDR and CDRW.
Fire up your burning software, select 'audio CD' as the type, select your wav or MP3 files as the source and burn. Make sure that 'finalise' is set as most audio players won't play open or unfinalised discs.

A different matter is what media your players will accept.
Commercial Audio CDs are pressed not burned and they comply with a standard called Red Book. Burned audio CDRs comply with Orange Book II and Audio CDRWs are Orange Book part III.
So there are 3 similiar standards differing on the reflective properties of each disc type. All Audio CD players comply fully with Red Book, how well they comply with Orange Book II & III determines how successful they are at playing CDR and CDRW discs.

The only way to determine what discs your Players will read is to try for yourself.

thanks for all the help, the message comes up that cdrw's won't play in regular stereo's or cars, right before i start creating the cd

If that is a warning that the burning software gives then it's just general advice. Some Audio CD players do read CDRWs , it's just that in the past CDRW support wasn't very common. I've noticed that more recently released 'discmans' and Car players are commonly quoting CDR and CDRW support.
Give it a try, if it doesn't work you can always erase the CDRW.