From what I understand if you have a preorder that constitutes a legally binding contract (i.e.: the dealer and Nissan are bound to offer it to you for sale first even though you can refuse and get your $500 refunded). Given there is a contract for sale in place before the Inflation Reduction Act becomes law then the current wording in the "Transition Rule" is that you would be able to claim the $7500 tax credit as if you purchased the car on the day you entered that contract (providing you ordered the car in 2022 -- not 2021).
Because the law (in its current form, before the House of Representatives modifies it) treats the car as if it went into service on the date you entered that contract.
I am NOT a tax attorney or accountant, so research for yourself, but this is how I read it and understood it after doing some research.
That said, the Inflation Reduction Act is not yet law and could be amended by the House before they vote on it. Then the House and the Senate will have to reconcile any changes the House makes.
Personally, I think there are few things in that law that are going to be red flags for the House of Representatives. Of course I could be wrong, because that would assume that Congress is smart:
1. The way it is written now, it will likely stifle electric car sales which would hurt the economy and would hurt the Democrats in the fall mid-term elections. The Democrats control the House and they will probably not want to do that. They will likely have to allow more of a grace period for U.S. manufacturing and U.S. battery mineral and component sourcing -- maybe enforcing those requirements at the start of 2023 or by August 2023 (for the 2024 model-year vehicles), but not enforcing for purchases prior to that.
2. The $80K cap on SUV's will likely need to define what an SUV is. Are the Mach-E, Ariya, EV6, ID.4 or Model Y considered to be SUV's? Where does wagon/crossover end and SUV begin? I think Kia calls the Niro an SUV.
3. The MSRP price caps for qualification likely need some annual inflation adjustment if this law is even going to make sense in 2025 or beyond. I doubt you can hold prices under those levels for the next 3 years to qualify for the tax credit. You don't want to match the social security cost-of-living-adjustment (COLA) each year since this law is suppose to encourage lower pricing, but you gotta do something -- like scale at 50% of COLA . For that matter, the tax credit should also scale at 50% COLA to keep encouraging people to buy electric.
4. If it is not spelled out already, allowing one tax credit every 3 years is fine for a single file -- but joint filers should be allowed 2 tax credits every three years since they will likely buy 2 cars. I like this provision since it prevents people from buying cars, taking the tax credit and then flipping the car at MSRP (or more) and playing on the short supply -- but you have to be reasonable when 2 people are being considered. This may already be in there and I have not read the full text of the bill, but nobody has reported on it.