I fully agree with tango, My previous car was an x trail and I used these, The shape of them means they dont vibrate and wobble all over the place. I now use them on my subaru still fit perfectly.
When I towed with an X-Trail I used SMAT weekenders but I am not sure they are still available. I would go along with the Milenco Grand Aero mirrors. Had them on couple of tow cars after the X. Personal preference would be to have the convex versions although opinions differ on that subject.