Dogs in the Wind

Today was a gorgeous warm day and I had the windows down in the car. Of course that was the cue for my dog to stick his head out the window so that he could have the wind in his hair - and I mean the hair all over his body! So here's my question, not an original one: why do dogs love to stick their heads out of the window of a moving car but hate it when you blow air in their faces? If I blow air in the face of my dog, he immediately tries to stop me by licking my face!