Toyota could have stacked the batteries so they would go from the bottom of the trunk to the parcel shelf above, that would have eliminated the little square above the battery, but it would have made it less deep, so there would be a bigger open area. They also could have redone the spare tire a bit, and raised the trunk floor, and spread out the batteries there. Then you would have the fold down seat. but I am sure they made the battery the way they did for safety reasons. The casing of the battery is designed to keep the battery intact in the event of a collision.

If my wife and I have kids soon, we are knida worried about where we will put the stroller, the diaper bag, and all the other stuff that goes with an infant. That is why we are considering trading our truck in for a SUV. (Still need to tow, so another car is out of the question, unless we keep the truck.)