Question Problem with shadows through model

I'm having a problem with the shadows projected by an object I created in Blender.

For some reason some parts of the model are letting light go through, even when it doesn't make any sense, as for example, the bottom of the car is a plane, so it makes no sense for some "hood" indents to let light go through.

What would be the problem here? As far as I can tell, the edges on the model don't have a gap or anything weird going on.

 

Here ya go.