In the late '80s/early '90s, the factory added 2 small holes for plastic pushpins that hold a steel plate over the original drain hole (which had a rubber plug in earlier years), and the whole thing is then covered in expanding foam. But that keeps water in the threshhold channel. So I removed all that and installed some spare cowl drains. These pushpins are spaced slightly farther apart, but it fits well enough to let water/trash drain, but keep most critters & flying mud out.
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