Hi Dave,

The roof rail comes with the car (Mine is signature trim). I got the crossbar from an online Mazda dealership and it is official Mazda accessory. I did install the cross bars myself. A several like two screws on each side of the crossbar. It is on the underside so it takes some patience to slowly tighten them while make sure it is threaded correctly (no cross threading). Otherwise, not really require a mechanic or the dealership to install them.

The rail already has the holes there so there is no guessing or drilling involved. Align the crossbar holes to the railing holes and put the screws in while holding the crossbar (so it won't force on the screw and risk misalign or cross threading).

Hope that helps!
Ivan

How is the Thule fit
 

Ivan,
thanks a bunch for your response. I am just curious how your Thule cargo box fits on the curved OME Mazda Cross bars. I read in another thread that “flat” things like cargo boxes don’t fit on the curved cross bars. What’s your experience and is there a lot of wind noise with the box up there? Thanks again Dave

My Thule Motion XT Alpine box is wider than most, 37.5". It fits well on the Mazda crossbars. Very little additional noise either with the box or just the bars on. I put the bars on only in the winter when I use the box for ski trips.