Is the best place to go the dealership or is there better aftermarket options?
The best place to go and buy from is where they have mats that look like trays. That are hard plastic trays that have a wall (not just a lip) around the edge. That type of mat holds the water and slush within the tray.
Back in the 70s we sold them at VW. They were custom fit, grey and made in Sweden.
Pants Savers and the like are useless. I have them, but I have a double layer of 6 mil vapor barrier under them with the edges sticking up around the mat by at least 5 inches. My ten-year-old carpets still look like day one.
I've never been impressed by what the dealers sold that were factory branded.