Brake light flasher module?

As others have said my wife purchased a vehicle with it, they said they are doing it because care about the safety of their customers. I'm calling that a lie because if they really cared and probably paid less than $30 and up charge to $399 it's about profit! They did wave it in the end though after she said that I would not pay for it.
Yes I did research and found it was not legal in the US however I had an incident several years ago where someone almost rear ended me at high speed after going through a toll plaza very early in the AM. Probably wasn't paying attention or half asleep. Saw them coming up on me really fast. Started pulsing my brakes very fast to get their attention. They got so close before they veered off that my vehicle was moved by their wind as they went to the brake down lane.

 

Anyone find anything that will work stock?