The TTC (Toronto Transit Commission) runs the only Unimog I've ever seen in Canada as a maintenance vehicle for a rapid transit line. It is equipped with a snowblower, crane and dump bed, and is also a hi-railer.
TTC Unimog by Ricecracker., on Flickr
This is a vacuum truck on a Sterling chassis. I especially like the colour scheme.
Sterling Vac Truck by Ricecracker., on Flickr