Anaheim police Sgt. Rick Martinez said Friday that the gray Dodge Caravan was found, but declined to say where. The men and boys, ages 2 and 4, remain missing.
Martinez says he believes the four are in the general area and may be trying to hide with friends.
Police have identified the suspects as the boys' biological father, 23-year-old Abraham Fernandez, and his father, 52-year-old Louis Mendoza Fernandez. The men live in Texas.