How do you fix the rear view mirror on an Audi A4?

I have a 1996 Audi A4 Avant S-line and the other day the internal rear mirror came away from the glass! I can't see how it was fixed as the surface that came away from the glass is just a smooth disc and only a round mark is left on the windscreen.





Can anyone help?|||The round mark on the glass is the glue that held it on there. Go to an auto parts store and get a kit to glue the metal piece back to the glass. Get some masking tape and put a piece on the windshield where the bottom of the metal piece is supposed to be, also put a piece to mark the location of one side of the metal piece. Then take a razor blade and gently scrape the remaining glue from the glass so you can put the mirror back to where it's supposed to be. Remove the metal piece from the mirror, the mirror usually slides on the metal piece from the top and has a screw to keep it tight. Follow the directions on the package to clean the glass and the metal piece, then apply the glue and line the metal piece up with your tape marks. MAKE SURE YOU GLUE THE RIGHT SIDE OF THE METAL PIECE TO THE GLASS! Use another piece of tape to hold the metal piece in place while the glue dries, it will take longer than a minute. The package will say how long to wait before putting the mirror back on.|||Some glass companies will reglue it for free. The ones that charge for it charge about $7.95-10.00. The glue they use is called minute bond. Only takes a minute to stick. Regular super glue will only hold it until the sun breaks it down, then it will fall off again. If you want to do it yourself, most auto parts stores and even walmart sell the one time application of minute bond but I would recommend getting it done at a glass shop. There is a little technique to it, plus if you get the bracket glued in the wrong place or upside down or backwards you have problems.|||Its held on with glue, You can get special wind screen glue to hold the mirror onto it. Get it as close to the circle as you can while glueing on the new one, And the glue can be brought from most auto stores or ebay. Like below





http://cgi.ebay.co.uk/Loctite-319-Rear-V鈥?/a>