Same here... there's currently a Cindy Sherman exhibit at the museum of fine arts. Going there involves taking the car, going to the store to get an electronic bus pass, driving to a bus stop, taking the bus to the metro, changing from the yellow line to the orange line, getting off at the Sherbrooke station, not forgetting to get two Montreal bus tickets added to the e-card, taking the bus to the museum... and redoing the opposite on the return way.
There's been a ton of shows I missed because they were such a pain to get to.
And that's depending on the weather and whether the metro is actually working or not. I once spent 2 hours in a bus that was stuck behind the big snowblower the city uses...
And taking the car means fighting traffic, orange cones, expensive parking (if you can find it) and hurrying up to avoid getting a parking ticket (that is if there isn't some odd contradiction in the signs on the pole like is usually the case in Montreal. Parking on the street in some parts is 3.25$/hour...
The other option is driving to the local metro, taking the expensive parking (if it's not full), walking about 1km to get to the station, then walking some more to go to subway level (about ½ km indoors)... and then you arrive too tired to actually appreciate anything.