Builder pattern

I need to implement Builder pattern without static nested classes. What is the best approach for doing it if I have inheritance? Let's imagine I have the following classes.

public class Car {
   private String brand;
   private String speed; 
   //getters an setters  
}

public class PassengerCar extends Car{
   private String capacity; 
   //getters an setters  
}

public class Truck extends Car{
   private String length; 
   //getters an setters  
}

Is it better to create one Builder class that will responsible for setting values of PassengerCar and Truck or we need 3 additional classes, CarBuilder, PassengerCarBuilder extends CarBuilder and TruckBuilder extends CarBuilder?