I bought side mirrors on Amazon that work great, can take multiple tree hits and not break. Some items I like to make such as a rear window from Lexan, easy to cut and shape, costs more than plexiglass
but cannot break. Roof? Any metal seller has plate aluminum, that and a couple of angle aluminum and you can make a roof for $100 that is much stronger than dealers plastic or metal roof.
I can sit or stand on my roof for a great view.