On the back of the i3 is a lot of glass that you can't see out of.
The glass below the portion you can see our of doesn't seem to serve a purpose.
The glass below the portion you can see out of just adds extra weight to the i3 where you don't want it.
BMW could increase the size of the portion you can see out of, replace the portion you can't see out of with Aluminum or plastic or carbon fiber.
The weight of the hatch would go down, and the strength would go up.
I see no drawbacks to this improvement.