Those job losses only impact the immediate community, and only for those people who don't find new jobs. I certainly won't notice the effects amongst all the other economic changes that take place in Ontario this year, I will continue to produce and consume as much as I would otherwise do. On the grand scale the jobs losses aren't tragic to Canada, they're just part of the continuous change that affect the economic cycle.
As far as the local impact, again the question is what vehicles will people buy to replace the Crown Vics? Here's a new type of vehicle that would be a good substitute vehicle for for taxi fleets;
http://www.vpgautos.com/
It uses the Windsor-built Ford 4.6L engine. So, if old Crown Vic customers buy these instead, they will continue to support that local economy.
Those job loses are only a "tragedy for the country" if you wear blinders. The big picture will tell the whole story.