My mum-in-law recently took away our car because i drive and she doesn't. what do i do?

me and my mum-in-law have never got along. recently, she found out that i drive my husband's car - which he doesn't use anymore. admittedly i didn't tell her that i was using it but that was because i had foreseen a scene. she's taken away the car keys, and is forcing my dad-in-law to put pressure on my husband to sell the car. they live in the same building as we do, and, well, in india, it is considered acceptable for parents t intrude in their children's lives. this, however, is unacceptable. what do i do?