leaking trunk

[motroman]

Discovered what everyone tells me is a common problem, a leaky trunk.

It seems that there's rust underneath the window panel by the right trunk hinge. Probably water gathered in that spot because of a plugged drain hole.

I can feel the loose rust underneath the panel. What's the best repair?

I'm thinking of cleaning off the loose rust underneath the panel and then using POR-15 or RTV, or some type of Epoxy sealant.

Thanks