It's up to the cop on the scene. Few Mexican traffic laws make perfect sense.
One sure way to get a ticket is to be approaching the intersection, see the blinking green light, then be accelerating like mad as you enter the intersection on a yellow.
It gets frustrating with Mexican drivers who think the little stick on the left side of the steering column serves no purpose (about 80% of the drivers).
Follow that car that has no brake lights into an intersection whose light changes you yellow as you enter. The car slams on the brakes forcing you to stop. Cars on your right are of course accelerating. Finally when the light turns red and horns blare, the idiot in front of you navigates around the cars surging in from both sides.
Of course the SAFE way to avoid getting caught behind an idiot is to stay in the right lane at a red light. Then you only have to endure people laying on the horn because you have blocked them from making a right turn on a red light.
Mexico is not kind to type-A-personality gringo drivers. But with the windows rolled down you can rapidly increase your colloquial Spanish. Phrases that involve pubic hair, your mother and various farm animals.
They may not have brake lights, or use turn signals but Mexican drivers know their significance.
The only rational defense is to drive predictably. Exaggerate turn signal advance warnings. Many times when somebody has their hood ornament stuffed up my tailpipe, I will give a 3-flash left turn signal warning before I turn left 200 feet later. Flash brake lights in advance of stopping or dramatic slowing.
When it's clear to do so on city streets I will pull over and let a tail gater pass me. Sometimes "keeping up with traffic means doing 45 mph in a 15 KmH (school) zone". Keeping up with traffic is like pasting a "Kick Me" sign on your rear bumper to the eyes of a lurking transito.
I do not know where the nutso "If you drive carefully cops will pick you out" came from. Mexican friends and my family laughed at this silliness. As a tourist, the common stereotype is that being a gringo you will not be driving like a Mexican. You will actually stop at ALTO signs and drive ridiculously slow somewhere less then double the speed limit.
Blaring horns are not a "Blatt! Blatt!" the unique report of a traffic cop's "pull-over" horn.
How many times have I heard (In Spanish) a cop say "You are different than what I was told to expect". Stereotype. A condescending elitist who believes they are immune from Mexican law. Sure, it's ridiculous. But rumors have a way of becoming credible when told often enough. Of course a predatory cop is a different animal. But until proven different I enter into a conversation believing the cop has had his tail yanked by fellow transitos.