I do too, and wish this was true there are “car safe” areas, but it’s really just best advice to not worry about it in the city. the Muni is cheap, Uber/Lyft are very convenient, and I just yesterday filmed a car smash and grab on Fulton street, in broad daylight by Alamo square. A lovely group of tourists were a few feet from their car when it happened. Thieves are very brazen and will be wherever tourists are, all it takes is to leave a coat or something in the back seat they think might be covering something up. I love this city, and violent crime is basically nonexistent, but property crime is very common and not prosecuted.