Great topic, given what the car manufacturers have been unilaterally deleting from their interiors.
He has a computer at home and no smartphone. Also owns tons of CDs. He can double pay for the same songs via some fee service to get some MP3's or whatever the other formats are. Or rip music from his CDs as he has been doing, and convert YouTube music videos as tpl and I do.
I wouldn't convert all those CDs, there are too many for the time it would take, and they won't "go bad". I'd make a decision about which songs I really want in my car, if any, for each CD, then move on to the next CD. Write down what I did on good old paper.
I undertook a project to convert my VHS tapes to DVD, and patience ran out before the week was up.
I fared better converting vinyl to MP3, scratches and all, with an Ion turntable, but that was because some of the songs weren't around elsewhere.