You could also use your sketch to Split the faces of the base surface, and then delete the faces you don't want. It gets a little confusing because the base surface is made up of so many surfaces, but give it a try and see what method you like best.
Use the Split Line command to project your sketch onto the faces of the base surface.
Select and delete the unwanted faces.
The good thing about this option, is you can prevent the cutouts from going into the headlight locations, but this would be fixed better by moving your sketch instead.