1Thursday 4:30 A.M. I am picked up in front of my hotel in Havana by Korda, Castro's bearded photographer, in his immaculate white Porsche. In the trafficless predawn he does racing turns through the city streets, opening the throttle wide when we reach the highway to the airport. The motor, fitted with parts adapted from other cars, growls like an airplane engine. But it runs well. Cuban mechanics, perforce, are among the best in the world.