I can’t extrude this series of faces. Why?
4Runner.blend (800.1 KB)
That object is quite a mess: You have one huge n-gon overlapping the other polygons. So, when you select everything and try to extrude, Blender can’t fathom what you are trying to do…
Delete the n-gon, then extrude. Or select everything but the n-gon and extrude.
There are also few other concave n-gons you might want to get rid of (bottom, marked orange/brown)
Thanks so much! My student thanks you as well!