No real advice other than what Jack said, but I did this on my '72 about 6 or 7 years ago, and never ever had one come off.
I don't know what Hall supplies, but you may want to find something to glue to the inside of the window as a cover... seeing the "bottom" of the mirror glued onto the window is sort of ugly... Practical though
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Charlie McCall
1972 DeTomaso Pantera #3847 (for sale)
1985 DeTomaso Pantera GT5-S #9375
"Raising Pantera Awareness across Europe"
http://briefcase.yahoo.com/gt5s_1985
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