I'm not sure you're actually reading my message. A bluff at the rear of the car is terrible for aerodynamics, but having a rounded shape is inconvenient for the

I'm not sure you're actually reading my message. A bluff at the rear of the car is terrible for aerodynamics, but having a rounded shape is inconvenient for the interior and storage. A compromise is made where you have a slope and then a bluff. The prius has this slope and then bluff. The flat surface is still bad for aerodynamics, it is not there to benefit them. Also stop just googling for wikipedia links then coming back with information you've only just learned. It's ok not to know everything.