My brother is in LA so my current plan is to ship the car to him and have him drive it until I go back. Dealer said that if they shipped to NC, some of their massive discounts would not apply.
The dealer is correct Honda currently has a $5,000 dealer incentive on the 2021 Clarity PHEV and $7,500 on the 2020 model. The current incentives are good through March 1st. However the dealer only gets those incentives from Honda if the car is registered in California.
Now that doesn't mean that you will automatically get $7,500 off of MSRP on a 2020, because the dealer can keep all of the incentive for themselves if they want to. But most seem to pass most if not all of the incentive on to the buyer, and some even add a little more discount out of their own pocket. Of course watch out for dealer add-ons that can negate some of the discount they are giving you.
There are several other rebates and credits available to California residents. But I'm not sure what complications you will face qualifying for all of those if you are not currently living in California. I would research all of that pretty carefully as far as what each of them may require as proof of residency, etc.
You may also know that there is also a $7,500 federal tax credit, this is available regardless of what state that you live in. However to get the full credit you must have at least $7,500 tax liability in the year of purchase. That is not referring to whether you owe money or get a refund when you file your taxes, it is referring to that amount of tax that is calculated on the 1040 form prior to subtracting withholding. I oversimplified a little but for most people that is the gist of it.
Another option would be for your brother to buy the car, register it in his name, and sell it to you later. Nothing illegal about that however you will have to pay sales tax/registration fees on the second sale, and also he would have to file for the $7,500 federal tax credit on his tax form since that credit goes only to the original buyer. And also some of the California credits require owning the car for I think a year.