Record those audio CD's and/or MP3's in the slower (if not slowest as in 4x or 8x, etc. for most reliability in playback) and test it out at one's own in-car stereo system first. The ones that I burn played nicely in the Nissan used for commute & in-town errands, but the Honda didn't like it & won't playback - yet, the Hertz rental seemed fine (mostly)

I carry a backup Motorola Atrix with a 32GB mSD and it's my fallback MP3 & MP4 player - a dual usb car charger plus a 3.5 mm "gold" audio connector, locate the jack & ding ding. It's ready for that "long" drive or whatever.

Yeah, I still got a 4GB FM charger/MP3 player that plug into the car's 12 volt outlet - one of the niece picked it up years ago in Guangzhou, CN while on a business trip, dirt cheap and came with a remote, LOL. Used it for a while - gathering dust these days in the plastic gadgets bin in the home den.