In the part of the Southern US where I went to college, if you were driving and a funeral procession came by in the opposite direction, it was common courtesy to pull to the side of the road and remove your hat, and wait for the procession to pass before resuming. That doesn't happen here in the Midwest.
I don't think I've ever heard the bit about holding your breath (though that is something people do when driving through tunnels) or lifting your feet before.