Finally resolved the pulsating vibration after having the car for 3 months. Got an appointment with a local Nissan dealer. I told them I already had the tires rotated and road-force balanced, which did not solve the problem. Also told them that the noise continued when turning left, but not turning right, which indicated to me that it may be a bad right front wheel bearing. Well, at first they checked the left front wheel and said they heard a noisy bearing, so they just replaced it. But that did not solve the vibration. The next day they checked the right front bearing finally, and found it "noisy" too. While replacing the right front bearing, the threads on the right axle were damaged. That meant they had to get a new right front axle. Took almost a week to get a new one. After new axle and right front bearing replaced, the vibration is gone. They thought the bearings were not installed properly at the factory and everything was covered by the Nissan 3-year warranty. I thought I read somewhere if you have a bad wheel bearing on one side, you should always replace the one on the other side too. Have over a thousand miles on the car since purchasing used, and everything else works great. I really like the car, and don't think I'll every switch back to an ICE car.