But when I'm a passenger in a car, I find myself muttering things under my breath. Little subconscious editorials of how the other person's driving. Almost Tourettish in a way.
When I think the person is going too slow, or has the opportunity to pass, I'll say "zoom, zoom". Or I'll sing, "pass the dutchie on the left hand side", which in this particular area would actually be correct about about 25% of the time. If, in addition to the people from Holland, you counted Germans as being from Deutschland, this particular part of the song could be eerily correct about half of the time. Though some might considerate it derogatory to call people "dutchies"..
I don't even realize I'm doing this most of the time. But once the driver breaks the code, they usually tend to get a bit irritated.
My ultimate muttering? "Ack". If heard, this would count as my worst criticism, since it means I believe my life is in danger at your hands.
Ditto if you hear me singing "Crazy Train". Aye, aye, aye.