I used SEM trim black 39143 on my:
-Quarter window trim
-front and rear windshield trim
-wiper cowl
-mirrors
-door handles
-wiper arms
It looks factory and has held up excellent. Goes on nice and dries fast. Couldn't recommend it enough.
For the pastic stuff I cleaned it well with dish soap and water. While it was wet and soapy I scuffed it lightly with a soft scotchbrite pad. Then rinsed. Wiped down with rustoleum wax and grease remover (or any paint prep safe for plastics) using a lint free towel. Let it dry. Then follow the instructions on the can.