JC, you forgot to mention that the side going up to the top of Lombard can be a challenge too. It may be straight, but it's VERY STEEP. So much so that you probably should keep at least 3 car lengths distance from the vehicles in front, just in case the driver ahead is slow getting from brake to accelerator and they start rolling back into you. Really need good confidence working the clutch, throttle and brakes to keep yourself from rolling back too. And the angle at the top is so steep, that when cresting it in a car, the hood blocks your view of the street and you loose sight of everything directly in front of you.
As the infamous comedian Bill Cosby said in one of his routines, the flower beds along the side of Lombard Street are where they "buried the bodies of all the people who didn't make it".