Car illustrations, cartoon cars needed

I need 25 car, cartoon illustrations in a similar style to the cars on [login to view URL] (this may lead to a further 24 cars but initially just 25 designs are needed). The designs will be based on images I send the artist of models of cars with some suggestions regarding colour and maybe in some instances some modifications. New to the site so not totally sure how the milestone payments work but would look to make payments every time a few designs are completed but we can be flexible on this in a way which is agreeable to both parties. It would be useful to see a portfolio of the illustrator/some work in a similar style, or even a rough draft when choosing someone for the project and some indication of time frames. Ideally I would like to work with someone with decent English as obviously communication is an important part of the process. Communication with the winning bidder can be done through the site, email, msn, skype etc. I would be looking for something in writing, upon payments which would assign copyrights of the artwork to my company I do have a ballpark figure in mind of what I think I should be paying for this job! Further details can be made available upon request. Obviously if things go smoothly then further work may be available in future.