Prius C 2012 - Removing Back seat

In the previous generations, there was concern about dust and hair getting into the fan and the traction battery and thereby, reducing the airflow over that cells and increasing the temperature of the traction battery. Since the C's air vent is underneath the left rear seat, is there a way to add an high flow air filter to it in order to cut down the dust and hair that might get into the traction battery? I was thinking of cutting up one of those cheap $1 furnace filters... Also, is there any easy access to the fan so that it can be cleaned out once in a while?

Yaris Hybrid , overview

Yes, and this shows what? That the Hybrid Yaris rear seat doesn't fold flat either because of the battery?

the rear seat cushion is attached to the top of the metal cage frame...

there's no real advantage of having that cushion not fixed.. which it really isn't since you can easily remove it.. however... there's really no significant increase in storage capacity with the seat cushion removed..

seriously, take apart the car.. and find out for yourself.. Toyota had a lot of design considerations to create a hybrid vehicle of this size... and one part of it was to sacrifice cargo space.