I have a 1990 Honda Accord DX. Few months ago, I found that its
trunk leaked. I caulked the tailgate light gasket. That fixed the
leaking problem of the driver's side but the passenger side still
leaked. I caulked it again, and eventually five times, to no
avail. I knew a new gasket would not help. But just to be sure, I
bought a new gasket from a Honda dealer to replace the old one.
And, as I had expected, it did not help.

There are two indentations on the edge (right and left) of the
trunk near the wheel. Now, when it rains, the right one is usually
full of water.

Any idea where it might be leaking?