I recently noticed an attractive aircraft at LGA. It had a large multi-colored "S" on its tail, reg # N503NK. It was from Spirit Airlines. It stayed less than a half-hour and was gone before I finished eating lunch. How can an aircraft get de-planed, re-fueled, re-boarded, so quickly? It's an A319-132. Anyway, my other question is the other Spirit Airlines all are painted in the "Digital" livery. Are they keeping the old livery or what?