3D car modeling is a very challenging task, which requires high level of skills, effort and a huge chunk of time. A car model has lots of little details, paying attention to all these little details and creating them, is what makes a model impressive and beautiful. Advanced rendering techniques play a part, but advanced rendering techniques can not make a sub-par model that lacks details, look impressive.
One needs a lot of references while tackling any new car project, starting with the basic plan of the car, although a good set of photographs also help as in case of very new models of the cars with no plans available or to modify a car, Maserati Trofeo model is a good example of this. I find most of the references from various sites on the net (but if the car is not too popular or one of those performance cars then things gets difficult) also magazines provide information and references.
Making 3D models from 2D sketches/illustrations, concept drawings, integrating various ideas into a 3D mesh.
Converting 3D scanned dense mesh to usable polygon surface, also converting multi surface object to a single unified mesh.
Converting Nurbs surfaces to subD polygon mesh or vice versa.
During the pre-production part of the project, you are encouraged to provide as much creative input and references as possible. this will expedite the realization of project.
You will be sent regular CG images seeking your approval and feedback at regular intervals especially during the initial stages of development. From start to finish you are given control over your freelance project and will have every opportunity to approve/disapprove sample CG images.
To ensure that the specific needs of your individual freelance design project are satisfied, costs for all Freelance Design projects are determined on a per project basis or per rate/hour basis and are specifically tailored to that individual project.
Once a quote has been agreed, usual method will be of a small deposit before commencement of project, interim payment as project milestone is complete (These will be agreed at the project onset), and a final payment once all 3D design complete and before release of the finished project.