Smart Cities are experiencing an increasing interest in academia and industry, underscoring the importance of efficiently utilizing sensor data to manage urban resources. The Internet of Things (IoT) is central to Smart City models, employing a variety of sensors to collect diverse data relevant to enhancing the urban living experience. Among the numerous Smart City applications, Smart Parking stands out, facilitating real-time updates about parking availability as already implemented in many cities. Still, the significant potential remains for advancing and broadening existing use cases, which is pivotal for driving innovation in the field. This paper addresses the exploration, classification, and potential enhancements of existing sensor-based use cases in the Smart City, particularly in Smart Parking applications. For this purpose, a literature review is carried out to structure existing Smart City use cases, and group brainstorming is employed to gain an understanding of innovating in the Smart Parking domain.