"Notify Me" Car Availability Button

I can’t seem to see a Notify Me option for notifying me when a particular car becomes available in my area. Can you either instruct me how to do that, or add that as a feature request please?

If you choose a car you’re interested in, then put your postcode in it will either say it’s available and let you book it, or let you put your E-Mail address in to get a notification for the next mass restock of cars.

If you aren’t given the option to leave your E-Mail address, it means the model you’re interested in isn’t going to be restocked, and it’s just a case of checking back periodically for existing cars circulating in the fleet as other subscribers return them, or choosing another model.