I normally flick my lights on and off if it's safe to do so seems to work better than flashing.
Ahh so you're one of them that drives with your lights off at night......
Or do you mean "off then on"?
Sorry couldn't resist but I use the tactics of switching off and on too. I think part of the problem is lots of cars have auto lights and dashboards that light up
yes, swap that round, oops