Earlier quoted context omitted.
Actually, the Passat has urea injection and is implicated as well -- though it didn't exceed emissions by as much as cars without aftertreatment. And the "couple of engineers" was in reference to the head of engineering and another guy. It wasn't implicating rogue low-level engineers. http://www.businessinsider.com/this-is-the-real-cause-of-the...
The current scandal is only about the "EA189" engine family with NOx traps for exhaust treatment. The new "EA288" engine family with urea injection was designed from scratch, and, I hope, doesn't need cheating software. Edit: the EA288 is/was -- at least in Europe -- also sold with NOx trap, but VW still claims it's free from cheating software.
EA189 was a Pumpe-Düse system able to get up to 280mpg in production vehicles, at the cost of high NOx emissions.
EA288 is a standard common-rail engine with AdBlue.