With just a few hours to spend in Montréal, we headed for Vieux Montréal, the 375-year-old center of town. City leaders and preservationists have done an excellent job here of keeping historic buildings and celebrating their legacy.
Entering this section of town, you feel like you are transported to Europe with brick streets, grey-stone buildings and sidewalk cafes and shops (500) for every taste. We re-grouped by starting with lunch in a cute café. There are so many, we finally selected one for ambiance and the thought it might rain. Once situated in front of large plate-glass windows with a good view down the main street Rue Saint-Paul, we shared a steak, salad, and pomme frites and watched tourists dodge raindrops. 
It had been so many years since we were there, we took in as much as we could before the encroaching thunder “drove” us back to our car. Highlights include the imposing City Hall, dramatic Notre-Dame Basilica, striking Notre-Dame-de-Bon-Secours Chapel (now a museum), imposing Marché Bonsecours, now housing trendy shops, and the lively Place Jacques-Cartier marketplace lined with sidewalk cafes and filled with street artists and performers.
The birthplace of the city is by the river and the Old Port area also has parks, rides and very large ROPES-style course fashioned to look like the rigging on an old ship.
Of Note:
There are lots of parking garages on the outskirts and we had no trouble finding one near Chinatown. Day rate was about $15 CA, which was reasonable. It’s hard to find the tourist information centers; I couldn’t even get a nearby site in the Old Town to come up on my iPhone, so be prepared. You can download a map/guide in advance from http://www.vieux.montreal.qc.ca/infos/pdf/attr_09a.pdf.
Note the traffic is awful, in every direction, construction is everywhere. Plan accordingly for it to be busy during peak rush hour times. We actually went to a Costco to get gas for our rental car, only to find out in Canada they require a Costco MasterCard, not Visa like in the U.S.