Rainfall is one of the most prevalent environmental challenges for road vehicles, impacting visibility and sensor performance. As automated features become standard in modern vehicles, ensuring sensor reliability in adverse weather is more critical than ever. Climatic wind tunnels provide controlled environments for vehicle soiling and sensor studies, but traditional spray nozzle systems lack independent control over rain characteristics, limiting their ability to replicate realistic rain conditions. Sensors such as cameras and LiDARs are highly sensitive to these parameters, requiring precise and repeatable testing for real-world validation. This paper presents a novel rain simulation system, the Vectorized Rain Simulation Apparatus (VeRSA), developed at Ontario Tech’s ACE Climatic Aerodynamic Wind Tunnel. It employs vectorized water injection and controlled droplet dynamics to generate realistic rain conditions that can be characterized, repeated, and benchmarked. Demonstrations are provided through rain characterization, perception testing of cameras and LiDARs, and early-stage UV dye tracing for vehicle soiling analysis. By overcoming the limitations of traditional systems, VeRSA significantly enhances realism, supporting both academic research and commercial testing. This integrated approach marks a milestone in advancing weather-resilient ADAS and autonomous vehicle development.