There aren't many places where spending a day in a parking lot or on an airfield is considred fun.  But fill that big paved slab with cones and cars and autocross transforms those locations.  A course is laid out with cones and drivers compete to see who can make it through the course fastest.  Cars are split into classes based on preparation level and speed.  This low-cost option is a favorite for many just getting into SCCA or looking to refine their skills later on.