Not common in those counties. It is very rare for a car break in to happen.

This is just not true... Car break ins happen almost everywhere in SFBA as long as you're in a relatively populated area. It's unlikely to happen in Loma Mar because no one is going to Loma Mar to steal shit. Catalytic converter theft is incredibly common in the rest of the SFBA along with other forms of theft.

Cat theft is common everywhere that there are sufficient density of cars parked outside overnight to make it profitable.