As a little boy, in Texas, my Dad always taught me to wave to other people that you shared something with, even if it was just having a nice drive. I always wave if I see a XF, or nice car in general. I think being friendly is something that is good to learn, just like helping others. I remember being 5-6 yrs old , on vacation and my Dad stopping to help someone with a flat or blown rad hose. I remember others stopping to help our family under the same situation. Different time i guess, but I will wave just the same.