Well, my understanding is that you can not get files off of the empeg using the "Emplode" software.
However, the empeg car unit houses normal IDE laptop drives. These drives can be connected to a regular laptop or PC (with the use of a special cable), and you can access the drive from there.
Of course, the drive is formatted for the Linux file system (second extended filesystem), so it is likely that you'll only get the files off if you connect the drive to a computer with a Linux operating system. Once the drive is connected and the file system is mounted, you can just copy the files to another hard drive (in theory). I've never done it before, but the process is pretty common in other similar endeavors.
So, technically you can transfer files off of the empeg... just the process isn't exactly easy (and if you take the drives out, you have to void the warranty of your empeg).
Kureg