try this
car cd players are typically more picky about media than computer drives (regardless of mac or pc)
especially in older car stereos
This is the test:
Hold up the cd-r in front of a light (better to try with several different brands), the more light that you can see the less likely that the car cd player will read this.
This is because the laser in the car cd players's laser goes thru the cd instead of reflecting back the 1111s and 0000s back to the laser pickup widget.
I have been burning cd-r's with my Mac since 1995 when cd-burners were $1800 (Pinnacle-Micro RCD-1000) at CompUSA, and cd-r's costed $10 each when bought in bulk packs of 100. yeah for real, 100 cd-r's used to cost $1000 not $20. So I have burned more than 5000 cd-r's since 1995. Data and Audio.
I have an older car that is picky about the media it will play.
The most reliable (currently being manufactured) is the Verbatim Digital Vinyl which are usually $10-20 for 50 cd-rs. These have black plastic on their topside (look like mini records) which the light and laser cannot pass thru.
these are my fav for audio cd-r's
data cd-r's don't matter too much which media is used
let us know your results