How to check the number of cars with an option?

[Thanoj]

I'm looking at buying a car, but I want to see how many cars came with a specific option. Is there a way to check for sure, or do I have to 'guesstimate' it? I want to see if it is a fairly rare option and if I should settle for a lesser model without the option.

The car is a Citroen DS4 with xenon headlights btw.

Thanks.