From someone who has been in the Auto industry for quite some time, looks like they changed things up a bit this year.
Instead of being 1st-2nd week of March, it is April 17th-21st and according to their map, there is no Mercedes, BMW or MINI. Not that its a big deal but its surprising that 2 of the 4 Germans pulled out when there is quite a bit of exposure from this event for the dealerships.
http://www.autoshowcalgary.com/