I have been putting books on thumb drives for awhile now by coping the book CDs in to the computer then out to the thumb drive. Pretty much every vehicle or radio that has a USB port can play books from a thumb drive. I put a bunch of books on one thumb drive and keep each one in a small zip lock bag with a list of what's on it. I have a few I keep in a pouch along with a few with some of my favorite music. I also play books and podcasts from my phone over bluetooth to my radio or plugged into the USB. Most libraries have audio books you can borrow for 2-3 weeks and play with the appropriate app, there are a couple of different systems.