jackson set serialization using object mapper

Lets say, I have below classes.

@JsonRootName(value = "car")
public class car {
private String make;
private String model;
//getters and setters
}

public class Automobile {
    private String color;
    private String type;
    private Set<Car> cars = new HashSet<>();
//getters and setters
}

When I serialize Automobile using below code
ObjectMapper mapper = new ObjectMapper();
mapper.enable(SerializationFeature.WRAP_ROOT_VALUE);
mapper.writeValueAsString(Automobile);

I am getting the output
{
  “Automobile”:
   {
    “color”: “red”,
    “type”: “four wheel”,
    “cars”:[{“make”:”Honda”,”model”:”cry”}]
   }
}

But I want something like below
{
  “color”: “red”,
  “type”: “four wheel”,
   “cars”: {
      “car”: [{“make”:”Honda”,”model”:”cry”}]
    }
}

How can i use jackson annotations so that i can get the output i want