How to use this 5 and a half width windshield?
That part is a little tough to use on its own. It is generally paired with another element to create a 6-wide windscreen (6567c02):



Without the outer part, you don't have any nice stud connections to work with, and as you mentioned the size is strange, so it would be challenging to work it into a build.

I imagine it is now obvious how this is used, but since you asked to see this in a set, here is one example: