A:
The case as mentioned in the question is an example of
Iqalah, which means rescission of the contract voluntarily by the contracting parties, the seller taking back the car and the buyer taking back the price.However, it is invalid to change the sale contract into a rental contract after paying a number of installments. (Part No. 11; Page No. 81) The correct procedure is to price the car and sell it either to the seller, who has already received a portion of its price, or anyone else and then buy the new car you like.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.