This is a drawing of my car done by my daughter freehand. http://i95.photobucket.com/albums/l143/anthony05gt/mustang.jpg?t=1164071117
It's already there. Check this one out that my son did. http://i95.photobucket.com/albums/l143/anthony05gt/350.jpg?t=1164073634
Your kids did some great work! You have to be very proud. Make sure you keep encouraging them they are very talented.
My daughter is 21 and my boy is 18. They have never sold any art. I'm sure they would draw other people's cars if they wanted.
I asked my son about that and he said $100-$150 depending on the pic selected. He said that the light on the car in the pic can make a huge difference in detail. I'm not trying to run a business here, but if somebody here wants a damn good drawing PM me.
You should have a pic that is free from reflections from trees and things. It should be exactly how you want it to look and be a file that is large. Like my drawing is 8-1/2'' by 11''. I would suggest a handfull of pics to choose from. Make sure the file is at least 1 MB in size to make sure they can see it well.