I think that the analogy has to be taken further.
If I have a Ferrari and you have a Volvo, then I can value my Ferrari, but if everyone has a Ferrari and no other car ever existed and I’ve never even heard/thought about the possibility of having a ‘volvo’ then there really is truly only Ferrari. Hence Ferrari is normal and rather ordinary.
If Volvo is sin, then is it not sinful to imagine/think about the possibilities of Volvo?
If Ferrari is good, then the only choice can be good and since all Ferraris are the same (perfection is the only good), then there is not freedom of choice. No free will.
To be ‘good’ you must always make the perfect choice, there can only be one perfect choice hence you are unfree.
Why is it bad to be unfree? Because, then you are unconscious, you have no freedom of mind as there can only be one perfect thinking pattern.