Quote Originally Posted by xPhantomSolx
I promise I'm not trying to be a dick... but you have a lot of improving to do. You're off to a really good start, don't get me wrong, but you have a lot of work to do before you're at a level to be professionally selling your work. To draw cars really well, you have to be an extremely technical artist... you can't just "look and draw" like you can with landscapes and portraits. You need to have knowledge of layout grids, multiple perspective points, root squares of design, light sources, all of that. That's what makes the difference between ok/mediocre drawings, which is the level that yours are at currently, and the really, really good auto drawings. You also need to know how to mix media to get a successful effect. Auto drawings should start with VERY light pencil work, outlining your basic construction lines and maybe some rough contour lines. Then you should decide what media you want a majority of your drawing in. Guache is amazing, but it's really expensive and really hard to work with. Graphic markers work really nicely, but it can be hard to get color uniformity using them. Personally, I like using pastels/chalk to lay down color. If you're using graphite, you need powdered graphite in a couple of different values, and some extremely fine point erasers to cut in your highlights. Start with your base values/colors, and add and add and add... the more colors you use as you build, the deeper and more realistic your values and shading will be. Use your erasers to cut in highlights, and if you're doing a grayscale, I would recommend picking up some white charcoal pencils. That way you can draw highlights on over darker values, and you can be sure to get pure, bright white highlights. If you're using markers, start light. Remember, you can't erase markers. Start light and add in your darker values. Then use some guache or possibly white acrylic paint to bring your bright whites back out. There's a lot of books out on the subject, I suggest picking up a few of them and getting some pointers.

Like I said, not a bad start, but a far cry from being sellable. Keep up the work, though.. the only way to get better is to practice.
bob ross in the house.