Your car player will almost certainly [B]not [/B]play dvds. DVDs use a different frequency laser than those used for cds.
And audio books don’t lend themselves to compression that can be readily played back. You can compress into something like a rar file, but that gets you nowhere for playing back on a cd player. You can also re-record the whole thing at a lower bitrate and possibly get a smaller output size, but 1.3gb to 700mb? I don’t think so.
What you could do is chop the original in two and put it on two cds. This assumes your car player can handle mp3 [B]data[/B] files. MP3 files do not equal CD audio.
Or if your player can accept usb flash drives, put the entire thing on one of them.