The poshest of the posh don't trifle with electronic alarms; they hire young men and women to watch their cars at night, and sound the Alarm Violin if need be.
I bet that's how they do things in Eagleton. Snobby jerks.
It takes a good amount of skill to do that, but not amazing levels. So other than that, this video is only here because 'cute girl does a thing', which is what youtube is for.
I played violin for years, she's not doing anything even remotely advanced on it. You can tell by her tone and intonation that she's not a bad violinist but the specific thing she's doing here isn't very difficult.