If this is a DS708 with a 4 GB card you can set the write protect switch, put the card
into a computer, copy the entire contents to a back up folder, then copy those files to
an 8 GB card and then put that card back into your DS708. You'll also then have a copy
on your computer. I've done this on both my DS708s.

 You are correct, Some how I missed that it was a 906, I assumed since I read this in the MaxiDas section instead of the MaxiSYS section he had the DS708, BUT you can insert a 32 GB micro SD card and then you can move some of the vehicles over to the SD card. I actually just un-install the vehicles I'll never use to clean up space on my 906. I use the card slot to back up my scan folder before EVERY update, just incase something goes wrong or I lose functionality, Then I can copy the scan folder back from the SD card.

Thanks