Selling an Eight-Lakh Vehicle for Twelve Lakhs on Installments

I, Shahid Khan, am running a business. I have a relative whom Allah ﷻ has blessed with great wealth. I requested him for a car. He himself does not own a car, but he told me to search for one. I found a car that I liked, and the price was settled. He then accompanied me to the showroom, paid the price in cash, and took possession of the car. The price of the car was eight lakhs rupees. He then sold it to me on installments for twelve lakhs rupees. All risks and damages related to the car are upon me (Shahid Khan). No extra condition was placed in between, i.e., if any installment is delayed or short, no additional charges or penalties will be applied.
Kindly guide me in the light of Shari‘ah whether this transaction is permissible or not. It should be clear that the monthly installment has been fixed at twenty thousand rupees, and the total number of installments would be sixty. Moreover, if due to some necessity I pay fifteen thousand rupees in any month instead of twenty thousand, this too is permissible. I must complete the full twelve lakhs rupees within a maximum of five years. If due to compulsion, the five-year period exceeds slightly, still no penalty or extra charges will be taken. Kindly clarify whether such a transaction is permissible in Shari‘ah or not.

الجوابُ حامِدا ًو مُصلیِّا ً

Yes! A transaction carried out according to the mentioned method is permissible and valid in Shari‘ah.

مأخَذُ الفَتوی

وفی المبسوط: وإذا عقد العقد على أنه إلى أجل كذا بكذا وبالنقد بكذا أو قال إلى شهر بكذا أو إلى شهرين بكذا فهو فاسد؛ لأنه لم يعاطه على ثمن معلوم (الی قولہ) وهذا إذا افترقا على هذا فإن كان يتراضيان بينهما ولم يتفرقا حتى قاطعه على ثمن معلوم، وأتما العقد عليه فهو جائز؛ لأنهما ما افترقا إلا بعد تمام شرط صحة العقد الخ (13/7)۔