mschulkind parent
Surely a carpeted closet full of clothes is better than a car
I didn't have such a place at the time, but I found one and results weren't as good as in a car.
Sound deadening generally requires mass to work for lower frequencies and the seats absorbed them all nicely. I got some reflections from - I assume - the windows, but they were manageable in comparison. Didn't even produce much of a standing wave when I tried.
Most people's closets aren't a room.