Cabin Air Filter?

[Intercooled]

My wife just had her Toyota Sienna serviced yesterday and they asked her if the cabin air filter had been changed. This was news to me, I never heard of such a thing. The mechanic showed us where it was. It was behind the glove box. He pulled out the entire box and exposed a slot where the filter sits. It cleans all the air that gets circulated in the vehicle. Also through the air conditionar and heater. The filter was pretty mucky and also had some leaves and other debris stuck to it. To get to the point, Does our Hummers have a cabin air filter?