First of all, sorry to hear of it (F#$@erz!) and hope remedied and back out there soon.
As a former 20yrs resident of SF (80s-90s), I can say the place has changed now....sad. Revisiting in 2010s for a conference weekend, I had my humble DD stolen out of Sutter/Stockton Garage but recovered after thieves joyride in 24hrs. The personal contents stolen from inside the car/trunk were worth more than the car itself, but thankfully thee was no damage to the car itself. (amazing) In short, when in the big city, best to not leave any valuables in the car. Don't even get me started on the towing/ parking /impound yard extortion racket to get my stolen car back from the impound yard. Dont EVER get your car towed in a big city......argh!
Now regarding neat old car security options:
1: Having a hidden battery cut-off switch hidden in the cab, under hood or in the trunk is not a bad idea. (Glad it's there)
2: Your dizzy on the fritz? The new Bluetooth 123s have an immobilizing/securty function in the app so you can ''immobilize" your car from your cell phone. (Haven't tried it yet but glad to have option)
3: Get an Agreed Value with your insurance company 'just in case' your car is not there when you return (Should probably up mine)
4. Situational awareness: do you really wanna take your pride n joy or the DD/commuter appliance to that destination/event/scenario?
I think I'd rather have some damage from the intrusion and frustrated thief than have my pride and joy stolen/MIA/gone....
HTH and I ever catch a thief.......ggrrr.....