ditto on the adapter source and cost: 5 x 4.5" trailer to 6 x 4.5" Nissan
(Also the 2" thickness makes sense for the added backspacing)
I sourced the adapters through
http://prowheeladapters.com/ great guy that works there was really helpful considering I ordered the wrong adapters the first time and he took them back no questions asked and applied the full value towards the custom ones. But they outsource to a company out of California that does their one off custom. I wish I would have written down the name of the company off the shipping label as you could probably save some dollars going direct to them. It took about 2 weeks to get them as apparently they botched the first ones they made so had to make new ones, I think they just forgot to place the order honestly.... I searched around and just googled "custom wheel adapters" and there is a few companies that just specialize in one of request so you might want to try that instead of going through a middle man.
Edit on the 2" thickness for the adapters I used. they are 2 1/2". I came across my notes where I calc'd out what I needed and 2" would have only put 1/2" clear from side wall of tire to trailer face so I opted for the extra 1/2" figuring that 1/2" might keep less mud, rocks, ice, slush from rubbing on the side. ultimately I would like to get the trailer bed lined to match the bed liner on the side of my truck, including inside the wheel wells but honestly.....I don't think I will ever pull the trigger on that do to cost.
