I understand the family rented a plane and they went and found the vehicle. It's a shame the troopers down there did no put in an effort to locate the vehicle.
They did not; a highway worker found the car at 3:30 and called NCHP, who called a diving team.
The helicopter was flying around, doing a search, and happened upon the scene when the highway patrol got to the scene.
There are variations that are being reported.
Howlin has an opinion based on her local sources.
There have been four reports that I have heard about or have read.
1) DOT worker was investigating scene and came across the car. - The question is why was the DOT worker on the scene
2) A helicopter rented by the family found the car and called it in
3) A helicopter rented by the family found the car at the same time DOT did
4) The uncle and another relative found the car
It is mostly likely what Howlin states but the facts will come out in the next few days.