Black Triangle hovers over car in city (soundless), street lights went out, "whoosh" acceleration, then street lights back on.

My dad was driving me to a friend's house.  At a 4-way stop in the Garden City area of the city, I looked out the passenger window and saw a large triangular object hovering over our car.  It had rained earlier, there were low clouds, and sodium vapor lights made it quite bright in the dark. The triangular object was very dark gray against the lighter low clouds. I noticed black lines underneath it, arranged very like a circuit board.  It was motionless and soundless for about 15 seconds.  It then slowly moved across the street at the rate of a person walking across a street.  It hovered over the convenience store on the other side of the street and then the street lights went out in the vicinity.  I could see the glow of sodium vapor street lights over the city about 3 miles to the south, and the glow of street lights ahead of me approx. 2 miles to the west.  All other lights were out. The object continued to hover for about 10 seconds and then "Whooshed" a! way at a very accelerated rate ... like a "cartoon whoosh".  When it was out of sight, the street lights in the vicinity came back on.  I noticed there were 1 or 2 cars at the 4-way stop.  We proceeded on our way.  My dad and I did not speak, which afterward I thought was very strange.  We only discussed it the day after.  My dad saw the same object and behavior, but he saw lights around the object - which I did not.
 About me: I was about 15 years old at the time of this incident (and an excellent student).  My dad was a professional symphony musician. I am a Systems Engineer and an alumna of an Ivy League school.