All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
Buying a car or house etc., through a Ribaa-based loan (i.e. interest and/or usury) is forbidden as we clarified in Fatwa 81662. Whoever does this is required to repent to Allaah and should determine not to commit this sin again.
As regards to the profit (or income) resulting from the car which is bought with a Ribaa-based loan, it is lawful if the car is used in lawful work.
Allaah Knows best.