The rubber mats that I have in my 2018 are from my 2011 LEAF. The rears fit perfectly, and the fronts fit almost perfectly. The floor pan is a little different on the side of the pan under the seats. But besides that, they work just fine.
NIssan's al weather ones (999E48Z000) are half the price of Weathertech and reasonably good. I only wish they'd had taller backwall on the driver's one. The "dead pedal" is not covered.
I bought them through Nissan's online parts store with pickup at local dealer and using their discount codes for accessories. Seems like a good deal.
I had the dealer include the all weather mats for my 2018 when I picked it up in the summer. I dont know the part number but they fit perfectly and are pretty decent. I've owned both weather tech and husky mats for other vehicles. These ones are not as thick but so far they are doing the job.
I guess I should find a part number for the 2018 mats, but I don't want to pay $200 for them or Weathertech mats. I could trim universal mats, but I don't work outside in Winter, if possible. I do have a set of crappy universal mats from my first Leaf that I'll use in the interim.
Well, THAT'S confusing! Ebay's parts compat-o-meter says no, and they tend to err on the side of just accepting what the seller claims. I'd like to get those $120 Nissan mats, but only if they will actually fit. I don't want to have to crouch down in that footwell on both sides, trimming universal mats to fit. I don't move well any more.
EDIT: The Ebay fit checker says yes for some listings, and no for others - for the same Weathertech mats. Weathertech seems to say that they are all the same for all years. Dammit.
I ended up getting a front-only set of exact-fit Weathertech mats on Ebay for $106.51 shipped. I almost never carry backseat passengers in Winter, and I have the universal rear mats from my 2013 to put in anyway. I would have gotten the Nissan mats for $120, but I keep reading that they only fit "pretty good." ;-)