I know it is only a movie, but… (spoilers)

I know it is only a movie, but… This movie was stupid and improbable from the get-go. It is easy to kill people and move their bodies in LA without being seen. Your brakes fail – why don’t you put on the parking brake, downshift, or turn off the motor. Instead, the car accelerates and you get killed. Cops in LA are stupid and can’t tell if brakes were tampered with. You get out of bed in the middle of the night and take off in your car and kill a woman. Your wife does not notice you’re gone, but your stepdaughter does, follows you and finds out where you have gone. Your stepdaughter, on Christmas break from college who does not like you, begins a Nancy Drew or Scooby-Doo type investigation instead of telling the police who was at the dead woman’s house. A license tag number would have worked. That would have been the end of the movie. You kill a man in a parking lot with your bare hands without anyone seeing you. You kill your stepdaughter’s friend, move the body, and make it look like another brake failure death. Somehow you manage transportation to make all of this happen. You also manage to spy on your stepdaughter all over LA while having a full time job.