I had my new Prius V for a couple of days and have folded down all back seats, as I am planning to sometimes put a mattress on top and sleep in the car, as well as for overall luggage space. To protect the seats, I have a large (water proof) picnic rug over all five back seats. Now I am wondering whether it is unsafe to have the seats covered or whether they need air around them. I read that I have to keep the driver seat free because of an air vent underneath and am a bit concerned that there is something similar in the back.
On our 2016 Prius v Three there is a hybrid battery cooling intake vent and grill on the right side under the second row seat. You might look for something similar and keep it from getting blocked. I've vacuumed mine a couple of times in the last two years.
Air for battery cooling will come under the seat provided you don't let stuff cram under the right rear seat or debris fall down between the rear seat and the trunk structure.
