I then placed a Boom Mat speaker baffle into the opening, which encapsulates the speaker. These do 2 things - they protect the speaker from any moisture that gets inside the door and the foam acts as a seal to the mounting surface (same thing I'd been doing with the weatherstripping during the other installations). Tip: there is not enough clearance around the 8" speaker to get the mounting bolts in once the speaker is mounted so those need to be in the holes first.