Rain leaks from roof on seats when doors opened during heavy rain.

It is a feature and not a bug. Close your doors to prevent rain gushing in.

 

It sounds like the problem is that there is no gutter-like area to catch all the water flowing off from the roof. While it is obvious that some rain will get into the car when one opens the door, it would be unfortunate if the car was actually directing additional rain from a larger surface area into the interior when a door is open.

Now I'm curious to look at the door frame next time I go out, to see what it looks like. I don't know about rain, but I do know that the day I bought mine, it was horrifically slushy outside, and globs of slush would just fall off onto the seat when I opened a door; sort of obnoxious.

[edit: Or does the original post's smiley indicate general joking around, making me look like an idiot? ]

 

There is no longer any regular gutter-looking device on modern cars. I remember one time a long time ago when climbing into my VW I misjudged the process not watching what I was doing at all and hit the gutter across my forehead--I had a nice red line for a while until the seeping stopped. And needless to say I would rather have gotten me and the car (the car and I) soaking wet.

On the Prius line there is a flat rubber strip that might possibly channel a little of the water but apparently not during a heavy downpour you describe. I'm afraid you should just grin and bear it imho.

 

That flat rubber strip is actually below the level of the frame around the door and does nothing to prevent water dripping. Actually, I doubt that much water from the roof drips in the direction of the doors in the ones I have seen. The top is what used to be called a double pagoda roof. Helpful for streamlining and directs stuff (air and water) down the roof to the rear window. The door frames seem to me to be level but higher than the rubber strip, so I think you need to move somewhere that it doesn't rain. In Florida, where we have had lots of wet weather lately, I had not noticed any particularly wet tendencies through the door, but I probably will now that you have pointed it out.

 

I notice water dripping onto the left side of the cover when the hatch opens in the rain.