At this point, it finally dawns on us how competent the X3 is as a long-distance travel partner. Sure, it's missing the xDrive35i's turbocharger, but our X3 remains decently quick. It offers plenty of torque across its broad powerband, and returns competent fuel mileage, too. So far, we're averaging 21.8 mpg.

The compact SUV effortlessly sails down the freeway, but is decently agile along the few back roads we stumble across. It feels like a high-riding 3 Series, one with cargo capacity that easily allows for my luggage and Shaffer's infinite supply of photo gear. Its interior offers the kind of comfort you don't even appreciate until you've been inside of it for 11 hours straight. Every time we'd arrived at our next destination, we'd get out without body aches or tiredness. That, and the cupholders actually work, which is huge for BMW.

The Texas speed run goes on hold as soon as we approach Dublin. Why? Well, located here is a little place called Old Doc's Soda Shop, where, in 1891, Dr Pepper was bottled en masse for the first time. Today, the shop still serves the original formula syrup, which is made from cane sugar -- not high-fructose corn syrup. There's also a small deli inside manned by an irrepressibly happy staff that makes delicious and inexpensive sandwiches -- a PB&J is $1.50, turkey is $3.

While the staff won't name Dr. Pepper's ingredients -- though they swear prune juice isn't one of them -- they do claim that the Frosty Pepper is "life-changing." After eating my sandwich, I opt for the concoction of vanilla ice cream and Dr Pepper syrup, and, after eating half, I deduce that by "life-changing," they mean that it takes a number of years off the back end.

On the edge of a sugar-induced coma, I point the X3 west again, and after a few more hours of complaints that Texas drivers don't understand lane discipline, we enter New Mexico. We take a straight and empty two-lane highway towards Carlsbad, and our driving behavior on it nets us the worst fuel economy of the entire trip, a paltry 18.5 mpg.