In 2002, filmmaker Michael Bay gave Kosar his big break by hiring him to write the remake of The Texas Chainsaw Massacre (2003) for Bay’s new horror shingle Platinum Dunes. The film opened number one and went on to earn over $100,000,000 domestically at the box office. Platinum Dunes and Kosar followed up on their horror debut with an equally successful remake of The Amityville Horror (2005). The two films cemented Platinum Dunes’ brand and ushered in a new era of horror film remakes. Kosar’s spec script The Machinist was produced in 2004 by Filmax International and starred Christian Bale. The film premiered at the Sundance Film Festival in 2004. Kosar also co-wrote the remake of George A. Romero’s The Crazies (2010). His television credits include Bates Motel (A&E) and The Haunting of Hill House (Netflix).