That's it for the bulb since it won't really be seen. Position it in the right position.
Time to make the glass that covers the headlight. Create a sphere, delete about two thirds of it and then squash it down a little to make it flatter.
Just like the windshield, the glass of the light needs to have some thickness to it in order to make it realistic. Put a "Shell" modifier on it to give it thickness. Play with the settings until you get something you are happy with. Collapse the stack. Chamfer the edges at the ends to sharpen them. Throw a MeshSmooth and Symmetry on it. The picture shows what it looks like smoothed. Position it in the right position.
Create a small box in the front viewport, just below the headlight with 1 length and height segments and 2 width segments. This will be the little tab with the screw in it at the bottom of the headlight casing.