The Nr Fairy,
It is not your CD-Burner that is the problem. It is the CD Player in your car.
Your problem could one or more of these:
1) Your Car CD Player cannot play MP3 Format. (If that is the format you are using.)
2) Your Car CD Player cannot play CD-RWs.
3) You Car CD Player does not like to color on the bottom side of the CD you burned. (Sony Car CD Players are known for this problem.)
Take Care,
Richard