In message , at
17:15:02 on Tue, 29 Sep 2015, John Rumm
remarked:
I also heard it reported that they did include Urea treatment, but it
was switched off during normal driving so it would not run out.

Not sure which is correct.

Could be both... IIUC some of the later model 2L engines do have the
urea treatment system, while the earlier ones were claimed to not need
it.

The ones with Urea treatment were 16-valve models fitted to Passats,
rather than the non-urea 8-valve models fitted to smaller vehicles, and
a few Passats.
--
Roland Perry