Getting an undercoating for your vehicle is always a good idea especially in places where it snows a lot like Canada. I'm not sure if where you live they put salt on the roads but when I lived in Minnesota they did and if you didn't have an undercoating your car would basically become a giant pile of rust.

I live in Muskoka, (on old highway 11) waste of time. Mabey in the 70s or 80s. Have a 96 Chev truck, 10 Jk, and 13 Fit. No rust problems yet. Just keep hosing of the salt come spring. And do not park in a warm garage.

I don’t think you need under car coating 

If you already have rust, an undercoating wont help you. Unfortunately, it'll just make it less obvious your car is turning into toast. I hate the gimmick people who advertise this. I live in WNY, and we have lots of salt. They dont undercoat ALL the parts, mostly just 4 points around the frame - if you take a can of the spray on stuff yourself, you can do it yourself with a tutorial, but mostly going to be a waste. eventually winter kills the car, better to spend on a car wash rinse once a week or two weeks than expect the rubber to work