Check the seam where the front cap meets the roof, notorious for that seam to leak, I will be doing mine with eternabond soon.
Maybe the clearance lights too, but those are a little far forward to get seats wet, but once inside the structure water can travel too.
Make sure window slides were closed tight.
Tom and Patty
The "Rode Crew"
2012 Itasca Navion J - Sprinter Chassis.