Is buying a car through the bank with 4% interest, by transferring the price of the car and the profits to my personal account first and then to the car company, considered usury (riba), knowing that the bank justified this by the necessity of registering the car in my name so that I can transfer it to Egypt in the future? And is repentance accepted if this act was a sin committed out of ignorance?

The transaction mentioned is a loan with interest, which is usury (riba); because the bank did not own the car but rather lent you its price. The fact that the car is in your name does not prevent the bank from buying and owning it before selling it to you. If the bank only paid you the price to collect it from you with interest, then this is usury and you must repent from it. If the transaction is different, please clarify it.