KMC Forums - whats this indie serial killer movie

I'm looking for a movie I saw that was probably made around the 2000s era, a man winds up stuck with a serial killer and ends up turning into his accomplice. This is not Henry portrait of... its not how to be a serial killer, the feel of the movie is strange its one of those movies that draws you in and has a menacing feel to it and gets you into the role of the killers, there is no other character that is important, its all about the connection between these two guys, the most notable reference I can give about this movie is the killer goes into an office building kills someone several floors up in the bathroom and then tosses the body out the window into the bushes below as the accomplice sits on the bench outside pondering what hes doing, eventually the killer comes with his car and the accomplice helps bag and dump the body. I think the car was a classic maybe orange or yellowish can't be sure though. I would love to figure this out and Netflix doesn't show it in my history, I watched it around 2009 or 2010. This wasn't a no budget or home camera film, it was fairly decently made and I can't seem to find it. I remember trying to Google the name to download it but it had a common one word name if I recall so Google didn't help much