Let's have a (hopefully) final look at Diesel emission cheating. This technical talk summarizes what I learned by reverse-engineering dozens of engine ECU software, how I found and characterized "interesting logic" which, more often than not, ended up being a court-approved "defeat device". What started as a "curious investigation" in 2015 to obtain a ground truth to widespread media reports of "VW being caught for cheating" ended up as a full-blown journey through the then-current state of the Diesel car industry. In this talk, I'll walk through the different implementation of defeat devices, their impact on emissions.