It's good to see you posting again. I thoroughly enjoyed
http://ecomodder.com/forum/showthrea...gns-25119.html.
One picture I have squirreled away in an album called
freebeard's Album: pieces and parts is this:
What I read at the time was that the main effect is acoustical. This is a valid consideration for the rear-view mirror. And it also suggests ways to test it with common house-hold appliances.