To be honest I’d be more worried about parking dings than it being stolen. I’ve got GAP to cover my losses if the worst happened and my car got stolen. With the GAP I’d be about £6k better off because of the discount I got when I ordered too.
I agree a garage is good but if it’s an organised gang it’ll only deter them so much. My S3 is always on the driveway as the garage isn’t wide enough but touch wood no issues in 2 years, a large part is where you live.