Someone may have added something for sound deadening . I've used bichathane for insides of doors after putting on door skins so the door doesn't sound tinny when closing. If used on wheelhouse you wont hear rocks and sand and some tire noise as much.Just my 2 cents. https://www.lowes.com/pd/Grace-Cons...Zljvbx0Zf0TVsqWPatcaAjKoEALw_wcB&gclsrc=aw.ds
