It also depends on the CD burner.
They use different width's of beam to burn depending on make model and age. Again the player also uses different widths and error tolerance. Add in the vibration of the car and it can't be read.
I have a LG slim line LU10 which produces DVD's and CD's which work 98% of the time on everything. The 2% of the time are in group 2 hire cars where they skip and generally annoy. If there has been a cock up in bookings or I get upgraded they work without a problem. Can't really complain as it only cost 20 quid and with my Aspire one and a set of 10 quid usb speakers turns it into a cracking little DVD player.