Undercoating is recommended to be applied when the vehicle is brand new to avoid trapping or sealing any corrosion and dirt. Undercoating can be applied to older vehicles as we would thoroughly clean and prep the undercarriage before application.
Is undercoating worth it in Alberta?
It's worth it if you get the dealer to throw it in on the sale. Undercoating is pointless, most cars have it (in some form) from factory, and it makes it harder to actually work on your car, as everything is covered in undercoating now. 3M is definitely worth it, but as mentioned, get it thrown in.
Do you really need undercoating?
Unless you are in an area where a lot of salt is used to clear the roads of ice and snow, undercoating is probably not necessary and can add significantly to the cost of your new car.