Upper 'lowest fare' without chauffeur car. Use of miles?

Afternoon all,
Just a quick question.
If you book a low fare in upper (Say, Z class) which does not allow the booking of a chauffeur car, can you book the car with miles like you would for a reward flight?
Just a quick question.
If you book a low fare in upper (Say, Z class) which does not allow the booking of a chauffeur car, can you book the car with miles like you would for a reward flight?