I've been driving for a couple weeks through very hard rain. I'm thinking it could be a combination of all the factors mentioned. I will start closing the cabover vent during travel.
It's raining here at home and I still have some unpacking to do, much less off loading the camper. I will check the butyl tape seals around the windows, the clearance lights, and tracks.
Another issue....since there are some Bigfoot people talking. Y'all ever replaced the rear awning fabric? My usually dependable RV repair shop says the awning is obsolete. They keep vinyl on hand and will custom cut it but I will need to take it to an upholstery shop to have the scrim sewn in. Anyone faced this?