Do you know what the size code (I,J,E,DD), or the chassis size, of your receiver/navigation unit. If so you can go to
http://www.crutchfield.com/ and get a list of size codes (I,J,E,DD), or the chassis sizes that will fit in the 95 maxima dash without any modifications. I think that most "double-din" receivers/navigation units are sized DD and will easily fit into the maxima dash.