[PeterD]

The whole of the front end appears to be the same colour as the roof when viewed in the game, but the sides seem darker. I even tried using different smoothing groups to link/group the sides into one and the top of the body and bonnet in another - but as you can see without changing the result.

The ambulance looks great To avoid the smoothing error in the model, in addition to detaching polygons you will have to move some of them (some fairly low number, say 0.0001 MAX units) if they refuse to unweld when getting imported. To detach polygons, select your model, press key 4 (edit polygons) if it's an Editable poly/mesh, then select the polygon and look for the button called "Detach" on the panel to the right. IF it is not en editable poly/mesh, apply the modifier "Edit Mesh" first (you can't export Editable polys with fatduck's script)

PS: When you press Print screen the screenshots go into IL2's folder