Does your car have a sunroof?
If it does, start with the sunroof drains. Open the sunroof. You'll see drain holes in both front corners. Try cleaning them out and then run some water thru them.
If it doesn't, I would check AC evap drains. Remove the vertical carpet lining on side of center console (just pull it off). You'll see a drain behind center console (ashtray height). Check if the drain hose (foam type) is deteriorating.
You should also check the outer drains in each corner of the windshield. If these are clogged, you shouldn’t be getting water inside. Unless you have a hole (rust) or a bad wiring seal.
Worth checking out because they keep control unit area as well as fuse box, brake area dry.