Pillarless doors while pretty cool have problems with wind noise after a certain amount of time. That is mostly due to glass being a slow moving liquid rather than an actual solid. So over time the seal between the glass and the car's body gets worse causing the windows to "flap" a little bit at higher speeds creating quite a bit of noise (pretty annoying).
That is complete rubbish, no offense.
While the theory is correct, glass doesn't "flow" that fast, nor to that degree. If it did, huge picture windows would fall out of buildings regularly. You could lean a broom against a window, and come back in 10 years, and the handle would be sticking through the glass like a barbed-wire fence in a tree trunk.
When your car moves, the air flowing over the shell of your car, the moving air creates lift on the surface of your car, since the car is shaped similar to an airplane wing (arched). This "lift" pulls on the windows ever so slightly the faster you go. Now, a new car doesn't have much issue, however, as the seals start to loose some of their pushback, as people use the glass to close the door, and as all of the flexible components inside the door ,that allow it to move so the glass doesn't simply snap when any of these pressures are put on it, start to loose their flexibility, that negative air pressure is able to pull just hard enough that it increases wind noise at speed.
My car's got pillarless windows.
edit: V= Thanks M-Bloc. I love it. Sure, it's an automatic and Fail wheel drive, but it was the world's lightest production v-6 at the time, and the auto revs to 7000RPM. Not bad. The fact that Clarkson would buy one over an Alfa was nice to see, too. Although, he's rather drive the alfa home, he'd rather spend his money on the Cougar.