While approaching Carlsbad, it dawns on us just how far the unstoppable march of technology has gone. We haven't used a paper map since we left South Carolina. We're able to find hotels through BMW's navigation system -- which thankfully doesn't limit operation while the vehicle is moving -- and call using Bluetooth to make a reservation. Then, whoever was passenger turned to their smartphone, where Yelp recommended the area's most infamous eatery.

That infamous eatery in Carlsbad is the Red Chimney Pit Bar-B-BQ, which from the inside looks like a log cabin and smells like smoked meat. Dinner? A heaping of fried okra, smoked cuts, hot links, and peach cobbler.

Day 4: Carlsbad, NM to Show Low, AZ
We head north along more barren two-lane highway, hang a left in Artesia, and make way for the Sacramento Mountains. We pass Cloudcroft, at 8600 feet, to find dormant ski lifts waiting for snow. The mountain range is short, and crossing it takes under 30 miles. Afterwards the road plunges into the flatlands that characterize so much of New Mexico. And then, in the distance, whiteness.

The White Sands National Monument and its 275 square miles of gypsum sand dunes highlight the horizon. The park entrance is west of Alamogordo, on Interstate 70, which also passes a missile range with the same name. You enter the park along an asphalt road that slowly winds its way into the sand. It's not long until the whiteness surrounds you.

We might as well be on Tatooine. The dunes go for miles, and kids sled down the hills. The dunes are in constant shift, but their movement is imperceptible. Climbing them takes some effort, but once you're on top the sand is firm enough to walk on. We get a few brief moments to admire the surroundings before heavy winds set in, causing massive, blinding dust storms that force us to take shelter in the X3.

We bear north again, make a left in Carrizozo and head west past Magdalena. Massive dust clouds hang in the horizon, and occasionally we have to drive through a wall of dust with visibility at zero. We pray the road continues after each brown wall. The X3 never feels unsettled, easily staying within its lane despite the 40 to 50 mph gusts.

After passing Pie Town, which we had hoped would be the home to a Willy Wonka-esque factory devoted to delicious dessert manufacturing (it was not), we press into Arizona. The temperature drops further and further, and soon, snow is falling around us. Shaffer insists we pull over for some photography; having planned expertly, he's wearing shorts.