I have not seen this movie but based on the podcast I had this theory about the bulldozer constantly running over the one car - it's a rapist. Given than there is no sex on screen, but there are perverts, a guy on coke would want to fit in some hardcore sex with their hardcore violence. He hates that one guy in the gas station, so what better way to get back at him than to rape his car in front of him. Also, it's a pedophile because it ran over that kid.