Seems like rat fur is more prone to hold bacteria, dirt, stale beer, etc. than other, less porous surfaces like tolex (which you wipe clean easily with a handi-wipe or paper towel).
I know, not very musician and rock 'n roll to be worried about dirt. LOL. But sometimes I have to put my cabs in my back seat and the idea of rubbing a piece of carpet on the floor of a dive bar and then putting it on my seats kind of wigs me out.
Did not read all the thread responses, so apologize if someone else already brought it up.