Thank you Jeff652 and talonmike. That nailed it.
When I got my latest Insight, I noticed some cloudiness on the battery cover, and then after several days of rain, there was moisture everywhere.
After popping out the trim pieces and the clips, I see what you mean there was not much there. After cleaning out the debris, I could see the seam.
Also, I saw just a little crack where the gutter meets the hatch, so I literally touched it with a small screwdriver, and what was there simply crumbled. It did not take much effort to clear out the old stuff.
Will get the sealer and the exterior grade double stick tape tomorrow and finish it up.
Hole on driver's side after clearing out old sealer
Hole on passenger side after clearing out old sealer