The covers are held in place by an extremely strong tape that is already on the replacement parts. One must thoroughly clean the old tape residue off, or it will interfere with a proper mount - it can hold the new part too far out. Care must be exercised in positioning the new parts.
Rust on B pillar cover.
Removal of B pillar cover.
Rear right cover trim.
There are aftermarket carbon covers available on ebay, however, these covers come without plastic top ending.