What is the button for with the little thing that looks like a vacuum cleaner on the dash of the 2000 cougar?
It is the traction control switch as listed in manual.
Although it is called a vacuum cleaner, it does not actually create a vacuum. Inside the cleaner there is an electric motor which drives a fan blade. This fan blows air out of the vacuum cleaner and this causes air to be drawn in to the cleaner at the other end. Thus the cleaner works by creating an air flow, not a vacuum.