Hey mate,
I had the rubbish thin standard boot carpet in mine, I bought a genuine one from eBay here:
https://www.ebay.co.uk/itm/Nissan-Genuine-Car-Luxury-Luggage-Cargo-Boot-Trunk-Mat-Liner-Tailored-KE8401E081/261274913101?fits=Model%3A370Z&epid=1016327867&hash=item3cd532c94d:g:xcsAAMXQb2JSHoGg
It came today and is spot on had all Nissan labels on the packaging.
Word of advice it’s worth making an offer too I think I offered £58 and they accepted. They are about £83 from Nissan direct so this was a bargain IMO