1. Make a data CD with the mp3's. But with the average mp3 being 1 MB a minute (easy to check) it's likely that you won't get 924 minutes on a 700 MB CD. So you would need 2 CD's at least. However, for audio books you should be able to convert the mp3 to another mp3 with a lower bit rate without losing much of the sound quality and then it might fit. This only makes sense of the CD-player in your truck is able to play a data CD with mp3's. Some are. Most aren't. The user manual will tell.
2. Burn as audio CD. Most CD-players nowadays will be able to play a burned CD. Some older won't. But you need at least 12 CD's for the whole collection.
3. Buy a player for your truck that can play mp3's from a USB stick or has the option to connect an iPod or another mp3-player.