There isn't much info out yet about the 2018 Mazda3's, even though some dealerships are actually starting to get them in (!).
However, today I found the following from Mazda USA, which gives at least an inkling, understanding that the US models do have differences from the Canadian:
Press release: 2018 Mazda3 Gains More Standard Equipment in all Trim Levels https://insidemazda.mazdausa.com/pre...azda3-pricing/
Webpage for 2018 Mazda 3 hatchback: https://www.mazdausa.com/vehicles/mazda3-hatchback
Webpage for 2018 Mazda 3 sedan: https://www.mazdausa.com/vehicles/mazda3-sedan
2018 Vehicle Brochures:
Mazda 3 Hatch ("5 door"): https://www.mazdausa.com/brochures-a...18&model=18M3H
Mazda 3 sedan ("4 door"): https://www.mazdausa.com/brochures-a...18&model=18M3S
2017 Vehicle Brochures
Mazda3 5 door: https://www.mazdausa.com/brochures-a...17&model=17M3H
Mazda3 4 door: https://www.mazdausa.com/brochures-a...17&model=17M3S
-SW