My car came with a new windshield installed and the rearview mirror from the old broked windshield, complete with broken glass adhered to the mirror mount. I got the broken bits off but am not sure exactly where to place the mirror on the windshield.

I will center it left-to-right but not sure how far down from the frame to locate the mount. Plan to put the roof on and try to find the best spot but would like to have it somewhere near original factory location.

IIRC, it was said 4 1/2 inches from the top was good.

too high and it won't clear the sun visors.
too low and you can see out the back.

the sweet spot is as high as possible that won't foul the visors...