Would you like to regenerate the title as well as the summary?
Parking was on flat drivewayThis has been ongoing since I bought it 10 years ago.
Yes the storm that hit was 60mph.
I have never been able to understand the design and how it allows water to drain
The water is draining and flowing /dripping along the top back doors and seeping along the inside edge above the back seat.There are a few places that can cause the leak. There should be a thin rubber gasket around the edge of the opening for the cover to seal to. The screws go into "well nuts" that should have sealer around them under the cover and sealer put on the screw threads when you put in the screws.
If the rain is getting in past the fins in the back for wind or whatever it may be getting into the air conditioner catch tray, which has a plastic drain tube the goes out of it and comes out under the van, probably, the right side rear pillar by the door hinge. They can often be plugged and need cleaning out.
Short term and for a test, you can just use something like Gorilla tape and put it over the cover edge and to the roof to seal it temporarily without removing the cover.
Where is the water coming out in the van? The tailights on 210s are also known to leak often.
Yes, the interior of the cabinet should drain out the back, but it will only if the van it sitting nose up on many of the Roadtreks. This was mentioned by others earlier. The goal is to make sure the top of cover on the roof surface is not leaking into that area in any wet weather. I would check that area first with water to see if it leaks into the cabinet area and if it leaks either tape it off for temporary fix or take it off and fix replace the gasket and check for stripped screws. Be aware that some users have found the screws stuck in the nuts and the nuts spinning, requiring grinding out the the screw heads to get it apart.I see the areas you refer to. The trim around the back entrance appears to be the drain ports. I might try to run a light flow from a garden hose to see if the ports are lined up properly. in the mean time I plan to take swimming pool noodles and cut them the length of the vents and insert them in the vents when not using A/C and heat. Some type of louver system should have been designed to address the problem.