Gone
(2006)

Having found Alex's cell phone the night before, Sophie yells at Taylor asking what happened to her boyfriend.  He says something about they need to talk about what Alex did to her.  She cries and they argue back and forth - then she runs to the car, he tries to grab her but she knocks him down.  She pulls the key out of the trunk door, jumps into the car and locks the doors.  Taylor punches and kicks the doors demanding she unlock it.

She tries to start the engine a few times, gets it started and pulls around, a pile of camping equipment falls out the back and then the car stalls.  She turns to look and sees dead Alex among the things that fell out.

Taylor, now in the back and leaning against the screen divider, tells her to put the car in neutral to start it so that it doesn't die again.  She starts it up again and pulls onto the road again and Taylor uses a Swiss knife to pull back to screen.  Sophie drives kind of wildly and Taylor almost falls out the back.

He tells her that they need to talk about, "us," and that Alex attacked him because he knew that Taylor and Sophie had gotten involved.  He pushes around the screen to try to grab her, getting scraped on the screen.  She stops and pulls forward a few times, catching him on it, injuring him further, then she notices he's fallen out the back and is lying in the road gasping.

She puts the car in reverse and backs into him and then drives off, leaving him dead in the road.  The last shot is of her driving - she cries a little - then stops and the screen goes black. 

Thanks Linsey!