If you contantly have source of ignition and add fuel, there will be a time when mix is just above sustaining near ignition source and more rich elsewhere. It d

If you contantly have source of ignition and add fuel, there will be a time when mix is just above sustaining near ignition source and more rich elsewhere. It doesn't take that much pressure to blow out windows in a car, it doesn't need to be properly mixed at right ratio in whole volume of car. It doesn't even need to be explosion, but very fast burning will increase pressure enough to blow out windows.