How do you determine when to say "drive down there/here", and "drive up there/here", or "I'm shooting down the street", as opposed to "shooting up the street". Or, "What the hell is going on up in here?" and "What the hell is going on down in here?" When do you use up and down to refer to the direction of a place?
For the most part you are free to choose between the two as you see fit. A shooting up the street and a shooting down the street are generally interpreted by the listener as meaning the same thing -- that a shooting occurred somewhere on the street a short distance from the contextual reference point.
In AmE, for longer, geographical type distances, we generally use Down if we're traveling Southward and Up if we're travelling Northward. If you live in Kentucky and I live in New York, I say, "You should dive up for a visit sometime." You might say, "Fly down for a visit.
Along those same lines, if you and I would travel primarily East/West to visit each other, one of us in Missouri and one in Colorado for example, we might say, "You should fly out and see me sometime." Or you might say, "You should drive out and see me some time."
Up In Here and Down In Here are very slangy usages and would be understood contextually.
For the most part, however, very little meaning is given to the prepositions used in those constructs.