My car doesn't have a USB connection; the closest solution I can think of is a tablet with music. I'm looking for an 8-inch Android tablet—one that isn't too old—capable of running Termux.
I have a pair of Moxee Tablet 2. These are old but may work for you, no longer works for me. My two 9 y/o niece plays Minecraft on them but they are too laggy for that now. They are in good condition, will take some pics in a bit.