I'm not sure why but 180's pictures in post #17 aren't showing up so I'm not sure if he used the same thing or not,

Anyway, This is what I used to seal up the wing on my SRT-6,
It's an EPDM weather strip I picked up at Home Depot. It easily splits in th middle so with one side of it I just followed the groove on the back of the mounting plate.
Put it back together and hit hard at the car wash.
No leaks
Frost King E/O 5/16 in. x 1/4 in. x 17 ft. Black EPDM Cellular Rubber Weatherstrip Tape-V25BK - The Home Depot


I also used two coats of clear Rust-Oleum LeakSeal on the bottom of the wing's mounting pedestals to prevent them form rusting after I sanded the rust of. It also worked great on the bottom of the passenger doors.