1965 Dodge Dart, Rain leaking in to the coupe

Seam seal it. You can cut the opening bigger behind the fender bigger to get to what you cannot get from the inside. Cover the rust with as much "Chassis Saver" or "POR15" as possible and let dry. This will help to seal it and allow for adhesion of the brushable seam sealer. Remember apply everything from the top and bottom. POR 15 makes a brushable putty in a tube gets solid like a rock. Depending on the hole size that will also work.

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