Desmond, I want to see the results of a fruit juice tetra pack (prima or similar) filled with an ignitable mixture of oxygen and acetylene (simply insert oxy set nozzle into said tetra pack through the straw hole, fill to swollen, duct tape the straw hole and ignite) that should shift the garage window a bit more and provide an interesting picture (if the camera survives) as well as test out the speed at which your trigger reacts.
BTW, wear ear, eye and gonad protection ya crazy bugga.