This video shows the how Peugeot 508 RXH Hybrid4 Diesel cools the hybrid battery.

So the Blower pushes air from the intake, passes through the high voltage battery then blows to exhaust.

I was curious to see if this car had any air filter and unlike the 3rd Gen (and up) Toyota Prius, it does not have. Has you can see in the video the system is a bit dusty.

What do you think should it have?