Anyone who's circled a busy parking lot or city block knows that finding an open spot can be tricky. It all can turn a quick trip to the store into a high-stress ordeal. To park in these environments, autonomous vehicles need a visual perception system that can detect an open spot under a variety of conditions. Perceiving both indoor and outdoor spaces, separated by single, double or faded lane markings, as well as differentiating between occupied, unoccupied and partially obscured spots are key for such a system -- as is doing so under varying lighting conditions. Not every parking space is a perfect rectangle.