the last image of your car i just saw is looking great!
Far far far be it for me to crit it, but i was once told a great golden rule about modeling anything with panels, never change the direction of an edge to coinside with a panel gap, make sure your panel gaps are offset slightly from the begining of any curves , bulges or general changes in direction of the contours, otherwise the mesh smooth etc will accentuate the effect.
Im thinking of where the back wheel arch begins to curve after the back door panel gap...
very good lighting on your render by the way!
free memory low..exception thrown