What's the best method of removing polish deposits (Zymol) from black (knobbly plastic) trim ...any advice much apprieciated!

 

A good clean with an old toothbrush (Or the other halves and keep quiet )and then some 'back to black' should do the trick.

 

Johnsons baby wipes work a treat

 

rubber eraser has been known to do a good job

 

This wouldn't be the black nobbly plastic that sits behind the number plate on the front end of the car perchance?

Because I managed to get some on that too. I put a bit more wax down and gave it a really good buffing and it took it right out for me.