Torrance is okay. Not the greatest. Just like all cities, some good and some bad areas. Highly unlikely a volvo or bmw will get stolen. I threw $5k wheels on my one of my prior and daily driver and drove it all over the hood, south central, watts, compton not excluded. When it comes to a luxury car, insurance is your friend. I'm sure you have full coverage, they take it you upgrade.
Temecula is nice, but fck the drive. If you don't mind a bit of commute, I'd look into something like Cerritos. Thirty miles away, but a decently nice city. You'll go through hell on the 91 though. Carson might be okay, but go to a nice part. Close to torrance, but it depends on what parts you stay. Thefts occur and if it's not a fixed up honda it'll be for sound systems.