The actual car is white with sponsors graphics but I couldn't face that, so here it is in a random colour that I still can't work out what it is.

Pastel dust scraped from the stick onto the paper and blended with cotton wool using paper masking to get the edges more crisp. I used some talcum powder to help the blending. The coloured pencils, pastel and markers were blended into a colourful soup on the page using a 10% grey marker. I still need a decent white pencil or pen for highlights.
Done on A4

Im going to put in a background once Ive decided a good colour in photoshop.