بسم الله الرحمن الرحيم
If you directly deal with the dealer and shopkeeper with no bank or finance company involved in between then it is lawful as per the Shariah to buy any vehicle or goods on installment provided the total price and duration of payment is fixed in the initial meeting of transaction.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.