Observer: It is known as the Inland Empire: a vast stretch of land tucked in the high desert valleys east of Los Angeles. Once home to fruit trees and Indians, it is now a concrete sprawl of jammed freeways, endless suburbs and shopping malls. But here, in the heartland of the four-wheel drive, a revolution is under way. What was once unthinkable is becoming a shocking reality: America’s all-consuming love affair with the car is fading. Surging petrol prices have worked where …