This is not rain. This is a drizzle on a very well maintained, center divided freeway, where the radar and ultrasonic sensor has a very nice reference (divider). Also with cars tracked in front. Example of (non-autonomous) driving in a real rain here for reference: https://www.youtube.com/watch?v=L3xKT98a3og

Because there was almost no rain in the beginning I jumped forward a bit and directly hit a point where the autosteer shuts off (a bit before the 10 minute mark)