@Pilou
Seems the reflexions of your renderings on the wheel car fender are "inversed" (very "dark" ) ???

You mean flipped normals? I think it's up to the Dino's lighting setting that darker areas,plus add a tonemapped effect that emphatize the local shadows
It's not a render,it's Moi screenshot.You can notice the seams on the carbody the Moi SubD converter did when imported...100% Moi :)
It's a solid like you see in your image,spending more time it is possible to build the inner parts and make better joints between doors and body and so on..



Final surface has slightly different seams,comparing to those in the image above because I did little adjustments before converting