In the Car radio replacement story I already mentioned the CDs that I used. In my current car radio the CD player is not included but it has an USB (and an AUX) input. In the meantime I bought a 64 GB pendrive to store the music there and listen to it while driving. Here comes the tricky part: the car radio supports only FAT and FAT32 file systems and on Windows the upper limit of FAT or FAT32 format is 32 GB. I tried several waysto fix the problem and finally I found a very simple programme called FAT32 Format.
I formatted the pendrive by this and since then it still works perfectly.