The factory ones, zero. At least that's my experience.How much wind noise do the cross bars make?
I have the rails, but saw a CX-5 at church without them and wish mine didn't.
Tagging for future use.One can cross-shop many sites...
mazdagear.com, mazdaswag.com, mazdapartsfactor.com, mazdaparts.org, mazdashop.ca....
Make sure you compare total prices + S&H + Tax.
These are big items. S&H can be pricy.
Mazdaparts.org offers free S&H for total price greater than $100.