Forget about CDs and DVDs...
They're already outdated, for private use (i.e. are not convenient for MP3 files, and other media). MP3 players and MicroSD cards are much more convenient (also for private copies, like the ones you describe).
If your car stereo doesn't have them, there are lots of new car stereos that nowadays come with SD card slots or USB ports.
Or, possibly even better - since, it allows you to listen to music outside of the car also, and sometimes to also use Free Firmware (
https://www.rockbox.org/) on them - just buy a cheap car stereo, that has an AUX-IN port, and connect your MP3 player to it with a cable.
With an MP3 player and MicroSD cards, you can carry the equivalent of an enormous amount of CDs or DVDs on your pocket, or bag. And, only SD cards or USB pens, that you can connect to a car stereo with a corresponding slot or port, occupy even less space.
I just *love* the stability, much more bug-free nature, and also modular installation options, of Debian. Apart from the unfortunate adoption of "systemd" (viewtopic.php?f=20&t=129881&start=165#p671030) this distribution is *great*.