Once the body color is on, use "dry brushing" to bring out the details such as grille and trim that were raised using the burnishing tool.  Here I'm using a gray color to represent "dull chrome." 

For dry brushing, remove almost all the paint from the brush onto a scrap of card or paper.  You can see the smudges of paint on the card in the photo at right where I dried the brush. 

CLICK FOR LARGER VIEW