flash for cash

Etymology

 * From the UK practice of flashing lights at another car to indicate they can proceed, +.
 * From the flash of the camera's light.

Adjective

 * 1)  pertaining to a scam where a motorist flashes their headlights to indicate to another driver to proceed against normal give-way rules, then runs in to them and sues for damages.
 * 2)  pertaining to speed cameras.