I used to fix cars for a living. Sometimes it involved “cracking” alarm & immobiliser systems. My clients all claimed they broke/lost their keys to their car - most of the time they were believable (car stuck in front of their driveway, etc). Sometimes less so, but I’d do it anyway because I needed the money and I had no proof of the contrary (innocent until proven guilty right?), although given the sad conditions of…
In Russia and, I guess, similar countries, it's quite rare to encounter a car which isn't protected by an external protection system (not sure how it's called in English, in Russian it's usually called "Сигнализация") which includes shock sensors, alarm system, remote control and car block which protects some vital engine circuits. There are systems with dialog protocol between remote control and car with actual encryption inside, so it might be not so trivial to break it. In practice such cars are either stolen inside trucks or an entire system is by-passed by a separate automobile computer connected directly to necessary engine sensors, ignition coils, etc. Quite clever technique, you don't need to bypass protected electronics if you can bring and connect your own electronics.