Lord,
You're right and it looks like its a real project. Part of the problem is the condensate drain tube is too short so when the water comes out it traces back to the firewall and drains back in the cab. I fixed this problem by using silicone to seal the whole opening.
I did find another source of my water leaks. it appears as if the windshield wiper housing for reasons unknown drains into the inner fenders, and there is no way for it to drain properly which was running into my floorboard. I'll try to attach some image so you can see my fix. I removed the water diverter and just added a hose on each drain to move the water directly to the ground.
Regards - Mike

This is the stock diverter dumping into the inner fended with insulation in the same location.

This is one of my drains under the coach


You can see just to the right in the fenderwhere he original drain was there is fiberglass insulation in the same compartment where it was dumping the water!
