How do I know what I have?

I picked up a new ride last week. I have a 6 disc in dash CD player in my 05 Magnum RT. I don't have any badges or anything else but I have 6 speakers. 2 in the dash, 2 in doors, and 2 in rear, is there a way to find out if this is factory or something the previous owner did with out tearing things apart?

Ryan