My daughter (who lives in the City) and I took a 2-hour GoCar trip during a recent visit. I've done Segways, Duck Tours, Big Buses, etc. Nothing compares to the GoCar experience.
San Francisco is a highly tourable City due to its compact size. Thus, in 2-3 hours, you can see a lot of what San Francisco has to offer. There are enough choices based upon your interests that you'll likely hit your choice for major tourist spots during the drive. We took the Golden Gate tour which gave us a number of opportunities for photo ops at beaches, overlooks, and notable attractions like Lombard Street and Coit Tower.
Much of the fun comes from the car, a modified three-wheel motorcycle with a fiberglass body. You turn using handle bars, accelerate with the right hand throttle, and break with handbreaks like you would with a bike. Pretty much anyone can learn to drive this since there's no shifting. I felt comfortable in less than five minutes.
The car is NOT for the big and/or tall due to its size. It's also a bumpy ride so it may not be suited to someone with back issues, etc.
You have a choice of a 50cc or 150cc engine. Get the bigger engine despite the added cost. You'll need the extra power to go up hills.
Also, I paid for the insurance and, while I didn't need it, the condition of the cars suggests a fair number of people have at least minor encounters with obstacles and fiberglass can crack easily.
The GPS guided tour worked amazingly well (but ensure you have the right language before you get too far from your starting point). Nearly always we were given advance notice of turns, etc. And the general tour information was interesting and engaging. Be prepared, however, for some real street driving and hill climbs.