Could you give the link to where you ordered please. I am not able to find any websites where you can buy only the back mats separatelyThe website shows the 22" wheels config at 330 miles vs 348 for 20" wheels. But Tesla could have that wrong and it be a much bigger drop than 18 miles to use 22" wheels. We'll see what the recalibrated value is.
Honestly, I dig the new all weather mats Tesla sells. They fit perfectly! Unfortunately, that's only for the front. I've ordered the 2nd and 3rd row 3D Maxspider ones people mentioned. They haven't arrived yet to give it a review.