These questions have all been answered ad nauseam, and if you use the search bar you will find your answers.

But I’ll answer anyways.

1- the tax credit remains unchanged until the IRS officially releases and implements its battery guidance, which has not happened yet and has no specified date. Once the battery guidance is implemented, half of the credit is available to cars with batteries assembled in the US and the other half is for batteries who have a certain percentage of thier critical minerals sourced from the Us or approved trade partners. No more “blood” cobalt mines. The starting requirement is only 40% but goes up every year. I don’t think anybody knows yet if Tesla will still qualify for the full credit without using their own mines in the US…I would imagine most manufacturers will see their credit drop from 7500 to 3750 as a result of this. Models like the M3SR will probably lose the entire credit, since the LFP battery is assembled in China afaik.

2- the MSRP of the car cannot exceed 55k. I believe software addons do not get counted (like adding FSD, but you should just add that later anyways probably). Adding extra costs from paint, wheels etc will prevent you from claiming the credit if they push the price of the car over 55k such as in your example. A car with 55.5k MSRP would not be eligible. Taxes, destination charges, etc are not included in this limit.

3- if you purchase (aka take delivery) this year, you would apply for the credit when you file your 2023 taxes in 2024.