[deeesstoronto]

Nowadays it really depends on how the immobilizer works to figure out how to/if you can override it easily.

I'm familiar with a couple designs - and on my vehicle I found it trivial to temporarily override (with the wiring diagram in the service manual).

My vehicles are on the older end of having immobilizers, but on them automakers certainly didn't integrate it tightly with other systems. It is controlled by one of the main ECUs - but the lockout method is subpar.

Better integration of the immobilizer goes along with the development of new engine management systems - so there may be more integration on vehicles with the newest engine designs (but not necessarily if the engine descended from a previous design and they kept the engine management system mostly intact....).

Some immobilizers disable starting, some disable fuel pump, some disable ignition, and some disable injectors. The how these are electrically disabled also matters a lot.

It's still trivial to override the first two methods, and sometimes the second two, but at least the last two have the potential to require more than a wire to disable if they are better integrated with the ECU.

[Zach_the_Lizard]

The last two methods--disabling ignition and disabling fuel injection--can be defeated by bringing your own ECU and / or other chips so that your key unlocks everything.

That could even be quick, depending on the make and model of the car.

The next step is to make all components work only if they can verify the ECU is the right one via the cryptographic solution du jour.

But this also complicates replacing wear components like coil packs, which now have to be tied to a specific vehicle, and can be defeated with enough part swaps anyways.

Physical security is hard.

[PaulHoule]

There are different segments of car thieves.

There are some sophisticated gangs that are stealing the cars and chopping them for parts or shipping them to South Africa.

Then there are people who steal cars for fun.

The later are easy to deter with technical measures, the former much harder.

Personally I think there ought to be a "tough love" conversation with certain German carmakers about how they sell parts with the possible endpoint of them being kicked out. German cars are overpriced and unreliable and they seem now to be planning gas cars for centuries after the rest of the world moves on. If European car brands were excluded from international trade I think that would make the world better and not worse.