can't understand the reason for this product except maybe for very long term storage. even then, it would take about the same amount of time to just wipe it down. If you plan on driving the car at all your gonna have to wipe it down periodically.
I have bought one. Find it far better than putting a cover on as you have to wash the car every time to avoid scratches. It also helps to prevent things falling of the shelf on to the car .
I don't use a dehumidifier either so the Carcoon has big benefits for me.