"flashing the headlights" is correct and usable in written English.
Generally, it is used to describe a quick on-off action of a car's headlights to signal something to another driver. For example, "The driver signaled to me by flashing the headlights."
A computer can remotely disable the engine, lock doors, honk the horn, roll up the windows and flash the headlights.
It was his job to stay in the car and honk the horn or flash the headlights if someone was coming, the decision said.
The Uconnect system is installed in hundreds of thousands of cars made by the FCA group since late 2013 and allows owners to remotely start the car, unlock doors and flash the headlights using an app.
It also scans for pedestrians and animals along the side of the road (whitetail deer, I'm looking at you — thermographically) and will flash the headlights to let pedestrians know there's a car coming.
If the square was red, they were asked to continue driving and to flash the headlights once, in response.
I thought to signal the party by flashing the car's headlights, but when I looked back over, the group of dudes Theo was talking to were gone, and Theo was feebly trying to decide which way to run.
On a particularly dark, almost deserted road, the officer began flashing his headlights.
Flashing your headlights, driving six inches behind the (crawling) car in front, gesturing from the window and shouting remarks about a driver's ancestry are virtually the law of the road.
Watching from parked cars and flashing their headlights, young men tried to coax the driver, Abadi al-Majberi, toward their corner of the plaza to perform for them.
"He was also flashing his headlights in an attempt to stop the bus but was unsuccessful.
