It's possible in my opinion. There really is no structure in the rear besides the 4 mounting points for the rear suspension. The cabin is a good structural box with two rear aluminum curved bars coming out back for said mounts. The rest is not integral. You could cut all the sheet metal in the back out and it might drive fine. It's just for cosmetics and aerodynamics.
For space use the rear isn't flat on the bottom though. Only the spare wheel well cavity reaches the bottom. The rest is raised to where the ima box bolts on.
