My garage (under construction as we speak) is being built into a fairly steep hill (28% slope). The lower floor is a woodshop and "storage" (actually a guest bedroom and car-related library with a wood stove and a picture-window view of Anchorage, Mt. McKinley and the Alaska Range). A driveway will curve around and down to give access to the lower level (though no cars will be parked in that level.
The upper, main floor has two car doors for passenger cars, and a high door for trucks, where the 2-post lift will be. Then there is a mezzanine over the passenger-car side, for additional storage.
The east half of the main floor is built on grade, and the west half is on doubled trusses over the woodshop/storage area. Foundation wall construction is by a combination of block walls and 2X8's. Since the garage main floor is at the crest of a rise, we don't anticipate any drainage problems, but the block walls are waterproofed, insulated, and protected with a perforated perimeter drainpipe.
Since construction of my dream Garage Mahal is well along now, I'll post some details and photos separately.