I noticed the satin really isn't that satin-y of a finish, my radio bezel looks just like gloss even after 4 coats of krylon satin clear on top of the satin fusion.
I used the gloss on my exterior parts.
My front bumper/valance has been done a couple years & it still looks shiny.
The fender flares have got a little dull or chalky looking, but I've been lazy & haven't kept them wiped down with armor all. After a quick wipe down, they look like new again.