With rapid advancements in Autonomous Driving (AD) & Advanced Driver Assistance Systems (ADAS), numerous sensors are integrated in vehicles to achieve higher and reliable level of autonomy. Due to the growing number of sensors and its fusion creates complex architecture which causes challenges in calibration, cost, and system reliability. Considering the need for further ADAS advancements and addressing the challenges, this paper evaluates a novel solution called One Radar - a single radar system with a wide field of view enabled by advanced antenna design. Placing the One Radar at the rear of the vehicle eliminates the need for corner radars and ultrasonic sensors used for parking assistance. With rigorous real-world testing in different urban and low-speed scenarios, the One Radar solution showed comparable accuracy in object detection with warning and parking assistance to the conventional combination of corner radars and ultrasonic sensors. The simple single sensor-based architecture not only reduces signal processing complexity and development time but also minimizes interference risks that comes with multiple sensor setup. This innovation results in a significant reduction in the Bill of Materials (BOM) for manufacturers by up to 40% for rear/side sensing modules, lowering production costs and enabling more affordable ADAS-equipped vehicles for end customers. Additionally, the simplified design enhances scalability for mass market adoption. The research paper talks about the one radar performance in various use cases to validate the features such as Rear parking alert system (RPAS), Door open warning (DOW), Blind spot detection (BSD), Lane change warning (LCW) and Rear collision warning (RCW) functionalities, highlighting its versatility as a standalone sensor module for future autonomous systems. Keywords: Autonomous Driving (AD) & ADAS (Advanced Driver Assistance Systems), Parking assistance, Door open warning, Blind spot detection, Lane change warning, Rear collision warning, Sensor fusion, One Radar.