Did the CD-R have a label stuck on it?
Avoid using stick-on labels. They don't adhere well and they can cause the disc to be out of balance.
My Toyota 6 CD changer hasn't had any problems with either CDs or CD-Rs. It also specifically states not to use any stickers on the CDs.
I went through 3 CD players on my last car and only one of them scratched a CD when I hit a hard bump (which was why I switched it out).
Kevin
Yes, it had a label.
I....forgot?