Sentence:  So you sit in the car and listen to the air run out and listen to the rain and see the mud in front of the headlights , waiting for you , for your new spectator pumps , waiting for you to squat by yourself out there in your tight skirt , crying and afraid and trying to get that damned son-of-a-bitch tire off , because that is being an old maid too , if you <WSD>happen</WSD> to drive a car , it is changing the tire yourself in the night , and in the mud and the rain , hating to get out in it but afraid to stay and afraid to try to walk out for help . 
Meaning of the word marked with <WSD> tags:  chance to be or do something, without intention or causation