they tested teufel slackens out on the west coast mostly a bunch of graduate students, some of them from india. they quickly noticed that there's a difference between the car's emissions that were produced on the highway and what they produced in the lab. they tested the cars in the lab to get a baseline and then they took them out on the road with a portable technology that since by then had been commercialized iand they saw that there was something wrong. they didn't know at that point what was wrong just something was fishy and they published a study about that in early 2014. nobody noticed much but outside the industry, outside actually this subculture of people who follow the emissions but among those who noticed was the california air resources board which is the regulator that enforces the law in california and they were concerned enough they put together what they call a compliance project. they use the clout as the regulator to assemble a small fleet of volkswagen's and defended tons of testing. if the bolt slacken had been smarter they would have at that moment and said we did