Subaru outback leaky hatch-5th door

So I have a 2000 Subaru Outback. This car is nothing but trouble. The latest occurs after a rain storm, or car wash, or anytime the car interacts with water.

Basically: I open the rear hatch door and water comes flowing out of it. It looks as if the door hand has considerable rust on the mechanism (looking at it from the inside) and looks as if this has been happening for a long time.

Any ideas? When I run water over the car with a hose there isn’t noticeable water droplets or water running into the inside. But there is always water in the lights and tail lights (disconnected from rear hatch). How’s it getting in there?