My wife and I visited the site shortly after the car was uncovered. It is not uncommon in this part of the country for farmers to have used wrecked cars to halt stream erosion so the presence of a wrecked car in the creek would have conceivably gone unnoticed for years. We both agreed that what may have prompted the fisherman to contact authorities about the car was the discovery of two long lost cars in a lake in Oklahoma a few weeks before that solved two cold case disappearances. What was strange was that a home had been built about 20 years ago literally across the road from where the car was found and for all those years the owners never notices anything.
Thanks for the background. I used to live in Nebraska and it was not unusual at all to find cars in ditches or woods while we were out hunting. When we would go out on the river you would see entire banks covered with old cars for erosion prevention.