As we started to get ready to leave, a heavy rain cell moved in on us, so we went and sat down again for ten minutes or so and waited for it to subside a bit, then made our farewells and headed back to Yuba City.
We stopped at a grocery store to pick up a few things -- taking advantage of having a refrigerator in our hotel room -- Cheryl noted water on top of one of the boxes in the back of my van. It was only then that I discovered that a bunch of the rubber gasket around the rear doors has rotted away. This is not something I would normally notice because I usually park under cover and rarely have anything stored close enough to the rear door for it to get wet. Fortunately, the water did not appear to have penetrated through the box, and there wasn't much water anyway, so I wiped it off and moved the boxes away from the areas where the water is coming in.
I hope it won't be too difficult to replace those gaskets.