Get into a car. Before you do that make your gamesounds on default. Use headphones to feel the hole part of playing dayz! Makes more fun with headphones!
Ok get into the car and switch it on. If it doesnt work. you need a battery and a sparkplug to do so. So get some before you try to find a car!
Ok if you are in the car and still not deaf yet, put in the reverse gear and enjoy the nice carsound in reversing the car.
Or if you are musician, you need your well working ears in future, put down the gamesound immediatly befor you use a car, because otherwise you wont hear the music in future, because
the car made you deaf!

The cars are working at least. BUT THE SOUND? It sounds like idk something but not like a car. Maybe a little bit more bass into the sound would fix it. Sounds like a grasscutter or a chainsaw. And it is much to loud with default sound settings you get deaf in seconds.