I solved my issue. I loosened everything and then retightened all the bolts. I believe my front passenger side near the corner slowly loosened over time, thousands of miles, and then all the flexing from doing the New Mexico BDR. I believe it caused a small gap in the weatherstripping which let water in. I’ve tested it now in heavy rains and with a water hose and no leaks. Going forward I think I will check every six months or so. Thanks for the suggestion.