Strange UFO with blue light caught over Orange County, California

Ashley McAdams has filmed a strange UFO in the sky over Orange County, California on May 10, 2018.

While driving on the highway she saw a strange object with a blue light flying parallel with the highway.

The UFO is certainly not a reflection in the window because the object disappears behind the trees and at a certain moment the object even speeds up. Could it be a drone or is it something else.