Something to know about MB glass. The rear tends to be laminated ( like front glass ) rather than the tempered glass most cars have.

Laminated glass is two pieces of glass stuck together with a clear rubbery glue. This glass will crack and run but stay together. This glue tends to keep objects from penetrating the glass.

Tempered is a solid piece that will shatter into a million small pieces like a side window. If you want to see tempered glass break, on You Tube look up " Sovereign Citizen gets window broken ". ( Sorry this is the best I can do on short notice. )

There will be a marking on the glass that should note tempered / laminated or at least some code.