Day 1, Charcoal drawing and photo view.

Place the panel so it is at a 90 degree opposite angle to your vision and the image you are painting is directly above the panel. The top of the panel should be the bottom of the image view.

When the charcoal was finished I brush lined over it with Liquitex water thin painting medium to make a line drawing.
This panel is primed with gray acrylic primer so I'll be taking advantage of this when I start working with white acrylic next.

Day 1 gray scale

I cleaned up a few lines with white and called it a day, 8 hours.

Day 2 gray scale 2

First thing this morning I finished the gray scale and shot a picture of it. Now it's ready to paint.

Day 2

Today was an 11 hour day, I had to get the background in. Tomorrow is the last day I can work on this painting and I figure the car will take a day. I got two more hours in after this picture was taken. This is what 2 more hours looks like. Most of the work was done on the tree above the trunk
 

Now I'm ready to paint the car, I think it will take all day.

Another 11 hour day.  It's finished but.. 

The teeth in the grill were bears teeth, mean! 
They took an hour and a half more time then I was planning on and I ran out of light. I want to go back in the morning and do some touch-ups. The car itself is dark blue and Victor wanted me to be sure and put the two flags in the white area. Now what kind of stroke would make a 1/4 inch red and black and a white and black checkered flag :- p

Liquitex has two new transparent colors that are great.

First is the Acra Gold, a dark orange-brown duel-tone that undertones with clear medium  into a yellow. 
Permanent, PO 48, PO 49. Quinacridone Gold with Quinacridone Deep Gold.

The second transparent color is called Van Dyke Red Hue.  It is also a permanent duel-tone . A burnt umber mass tone with a seinna-red undertone.

These two colors together have a wider range then burnt sienna by itself.

I did notice in my new set of acrylics that Burnt Sienna is less transparent now then it used to be. Windsor Newton still has a translucent burnt sienna.