Not USB? That’s what I mostly use. The in-car software does a pretty good job of providing flexible access to the contents of the flash drive (e.g. sort by artist, sort by title etc.).
This.
In my country, apart from the video surveillance-overload, it is becoming more difficult to use an anonymous travel card and in any case they may still be recording data about the use of each anonymous card.
LOL. I’m guessing “no” on that one.