When you are surprised and grunt like a caveman.
When seeing an unexpected person, an attractive or unattractive person, any object or think that doesn't belong, or in a weird situation.
Ex girl friend walks in the same room your in and you give out a huah
When you get in your car and you just go, and you just do, and you just live.
"Carring is when you get in your car, and you just go"