i have seen buckets in the back of a fezza so it can be done,
but i think they may be too high and might hit the roof... problem is that the front seats are bolted to the floor and the back ones sit on the fuel tank. you would probably have to drop the fuel tank to get the bolts in. and unless you welded the nuts to the chassis or something, you would have to drop the tank every time you wanted to take the seats out
but its a nice idea i would like to see it done, just most of my cars dont have back seats at all lol