EDM Challenge #60

Here is my car. It was so nice on Monday that I took my new little stool and sat on the lawn to draw the car. I made it a little too big and then didn't have enough room. I almost think I liked the line drawing better. I didn't take a pic of it though so its lost now. I colored the drawing with Derwent watercolor pencils and then used a waterbrush on them. I got in a quandry when drawing this. I end up with questions like ... Should I color in all the black areas or not. Should I use cross hatching or just fill in with a brush pen, should I color it in or not. I wonder how other artists make this decision.