Water! Just plain WATER! Most people have never watched a glass cutter so
they never knew a simple trick. Before they score the glass, they lick their finger,
then drag it behind the cutter. That weakens the glass by IIRC 3 orders of magnitude!
So, a rock nick, some rain , a big bump, a twist (sounds like I am going to hurt my back again)
of the body and out magic a crack zips across the glass.
This is one of the reasons to repair "bulls eyes" or stars on windscreens. Just like evacuation
of an A/C system, one needs to remove the water before releasing the adhesives.