As 'Options' can have several abilities, a native type is not enough. Therefore you have to create another class 'Option' and add fields like description, price, title, etc.
class Option {
private String description;
private double price;
...
}
Create a class Car or CarModel to put in the title, etc and add a list of options:
class Car {
...
private final double FIXED_PRICE;
...
List<Option> options = new ArrayList<Option>();
...
public Car(final double price) {
this.FIXED_PRICE = price;
}
}
To make a price a constant is very uncommon, but maybe ok in our case. To assign a final field at class initializaiton you need to add a constructor like that one shown above.
You also need to add methods for adding and removing options:
public void addOption(Option option) {...}
public void removeOption(Option option) {...}
If a type of Option can only exist once in your options list you can make it a Set. To calculate the final price add a method that is iterating your options list and summing the prices with the fixed price from the car.