No 2017 and prior rear cargo cover WILL NOT fit 2018. For what ever reason, rush to market, Nissan didn't make any rear cargo cover available until August and now Sept 2018 for their new 2018+ models.
I know, I purchased my 2018 Leaf in March 2018 and the dealer told me the rear cargo cover won't be available until not and it is. here are 2 links. one after market, that looks very professional at almost 1/2 price. for ?$165 plus $76 for shipping from Ohio to Los Angeles, CA
= $240
https://www.cheapestfactoryparts.com/index.php?p=cart
while the dealer one is $275.00
https://www.nissanusa.com/vehicles/electric-cars/leaf/accessories.html
I know, I purchased my 2018 Leaf in March 2018 and the dealer told me the rear cargo cover won't be available until not and it is. here are 2 links. one after market, that looks very professional at almost 1/2 price. for ?$165 plus $76 for shipping from Ohio to Los Angeles, CA
= $240
https://www.cheapestfactoryparts.com/index.php?p=cart
while the dealer one is $275.00
https://www.nissanusa.com/vehicles/electric-cars/leaf/accessories.html