Audi and Mercedes both have high dollar, high technology diesel wagons on the market now.
From the article:
These modern diesels, most of them using on-board urea to neutralize smog-forming pollutants, meet nationwide emissions standards, are relatively quiet and start without swearing.
On-board urea reservoir? Ut-oh, snickering begins.
...and periodically filling the urea reservoir...
Bwaa,ha,ha. I wonder if that is a user serviceable function and if there is any, um, natural
substitute for the urea additive? The mind boggles.