My 4 y.o. son pulled the rearview off this morning. Glass was cold, and the mirror & tab came off. It also pulled a piece of glass off with it. I thought it was glue at first, but it's glass. The chunk fits nicely back where it came from. What are your suggestions? Clean it and glue it back in? Is the glass now suspect to breakage or is it ok to glue it back together and not worry about it?

If you want to, you can glue the chip back in place (or just leave it out - it will not help prevent breakage at all), then glue the mirror mounting button in a new location next to, above or below the original one. If you try to put it in the same location, it will probably fall out sooner.

As far as it being more susceptible to breakage, yes it is. How likely is it to happen?.... nobody knows. I have done it before (in my wife's POS landrover whose windshield would have cost over $600) and we ran it like that for 3 years until we sold it.

You can find the mirror mounting glue kits at most parts stores.