thanks for your comment.
The modelling can be improved, but - since I choose to use an existing IGS - I had to manually ‘mend’ the meshes once in Blender ( a real nightmare). Nurbs are great for perfectly curved shapes, but the meshes generated in the conversion process are really full of way too many vertex…next time, I will probably want to learn how to model nurbs surfaces directly in Blender.
Regarding the lighting: there’s one sun only, and I have used sIBL scenes just for that. Unfortunately, though, the sIBL GUI does not work properly in Blender 2.77a (I have opened a ticket for that, but I assume that Jed Frechette is not controlling the bug report continuosly). Anyway, even when the plugin was perfectly working (like in 2.72), the accurate positioning&aligning of a model over the scene is not a quick and easy task: the sIBL controls are great for lighting, but it seems to me that the GUI (GUI 4) is not updated as it should (you can
only rotate the scene-sphere, but no scaling nor location controls are usable). Which is a pity, since I think that sIBL could be a great tool.
I’ll try manual HDRI, then: and I want to better fix the materials for the car’s lights, snce there is too much internal reflection-interaction between the inner light casing and the external glass.
Once done that, I’ll post some more renderings.