Quote Originally Posted by speedminded View Post
Name one state in the US that "flash to pass" is legal in lol!
In California:

21753. Except when passing on the right is permitted, the driver of an overtaken vehicle shall safely move to the right-hand side of the highway in favor of the overtaking vehicle after an audible signal or a momentary flash of headlights by the overtaking vehicle, and shall not increase the speed of his or her vehicle until completely passed by the overtaking vehicle. This section does not require the driver of an overtaken vehicle to drive on the shoulder of the highway in order to allow the overtaking vehicle to pass.

Also, this below is from Wiki, so not a very credible source, but it's how I feel

Quote Originally Posted by Wikipedia, I know, it's a shitty reference
A driver hoping to pass a slow motorist in the "fast lane" is stuck in an awkward situation. One strategy is to signal a lane change toward the center median. Another is to flash headlights. A third, which sacrifices safety, is to drive very close to the "fast lane" driver's bumper (this is known as tailgating). In Germany it is common to signal a lane change toward the center of the road, as if there were another lane to the left of the "fast lane".
Most commonly, motorists will attempt to overtake the outer car on the inner lane either to continue at a fast pace or to pass a car that is simply going too slow in the passing lane. For high-capacity multilane freeways (three or more lanes per direction), many motorists often pass on the inner lane, largely in response to misuse of the "passing lane" by slower traffic.
I know it's illegal, but there is NO safe way for a non officer to enforce the passing lane laws. If someone doesn't know the rule, and why should they, I mean, American driver's ed doesn't touch on the left lane laws(this REALLY pisses me off), then they will forever cause problems by misusing the lane. And cops hardly ever actually pull people over for cruising in the left lane and giving them the "disrupting the flow of traffic" charge they deserve. I don't see why flashing the lights is considered rude, so long as you're not on their ass.