thx to all... found this post very helpful. Thought I would add that there's a lot behind the Chateau Laurier (note: not the Chateau Frontenac) off the Grand Allee that had 12 hr parking for 8$. This was weekend, not sure about weekdays. There's a VinciPark under the Chateau Laurier that had 7$ for weekday evenings and weekends but 6 hr limit. Enjoy!