An over-the-air update will not solve this one.
Not everything in the Tesla Model 3 makes users happy. Particularly, the trunk can surprise the owner in the rain if he/she decides to open it.
As Bjørn Nyland shows in his latest video - "trunk design flaw" - the water gets inside the trunk, as there is no other way for it to move off the lid without entering the vehicle.
Tesla Model 3
If Tesla does not find a solution to this, then the Model 3 will be cumbersome in rainy markets.
Other videos with Tesla Model 3 vs rain: