I'm trying to close the back of this windshield geometry. I think I successfully have by using the edge selection tool and stitch and sew. However, it leaves me with an unsightly weird looking plane and when I try to subdivide it, I can't get a result to look like the front of the glass. Any ideas on how to give this object smooth polygons (like the front) and close the back properly? I tried using Subdivison surface as well.
What about just nesting the object (less the added "back" and sides) inside a cloth object ) then you can set the thickness. Is that what you are after or do you truly want a flat plane to span the back?
In this instance you can think of the cloth as a normal-directed, full object extrude.