Everyone's probably been perplexed at some point as to why dogs love to stick their heads out of moving car windows. Turns out, it's not that they really like the feeling of the wind. It's because they get an awesome overload of smells.
It might seem strange to us, but consider that we only have about 5 million olfactory receptors, while a dog has more than 225 million receptors. Our olfactory membranes are about the size of a postage stamp, while a dog's is the size of a handkerchief.
To a dog, sticking his head out the window of a moving car is the equivalent of a human going from a standard television TV to a giant IMAX movie screen and trying to soak in all the colors and visuals that it entails.