Yeah, OEM all-season trunk mat is fine. But those fronts look way better than stock for people in cold climes. My car came with OEM all-season mats, but I'm thinking of selling them and buying the Weathertech fronts. Don't really need rear all-seasons that much.
Those are the liners which they laser cut and usually fit very well. Did they have the mats available? They would be similar to the Infiniti all weather mats and are of very good quality. I have used them on my last 6 or 7 cars and they always last the whole term of my lease, usually 36-48 months. They are really worth the money and made in the USA.