A 41-year-old local man, believed to be the driver of the car, was arrested for grievous bodily harm at the time.
This is now being treated as a homicide investigation by Surrey and Sussex Major Crime Team working in conjunction with colleagues in West Sussex Division.
More top news
Thursday night's weather for the west of the region
Thursday night's weather for the east of the region
You've sent us your pictures of the impact Storm Doris is having across the region.