factory/dearler installed 8-track players

[chewychevy67]

Here are some pictures of my speakers for my 8 track. This is what i figured would be correct. they are 1967 chevelle door speakers and grills. i will paint the grills the same as the interior and you will hardly notice them. nice and clean. i would like to mold to the speaker shape somehow some thin plastic to put behind the speakers so they don't get wrecked from moisture. maby a vacuum packing tool could be of use for this but havent thought that far ahead. anyone tried anythng like that before? would this affect the sound of the speaker?