sure, if you want to have the box extend above the seatline, and possibly have to fold the seats up to fit the right volume.
best you are going to get is maybe 4 cubes sealed out of the storage area in a GTi or golf using a conventional box because the area is also angled on each side, so its kind of a pain in the arse //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif