What matters to me is that this shouldn't be physically possible. I don't want a car that can be stolen using Bluetooth.
Many people refer to it as "relay theft" since historically it's often just a matter of relaying/repeating a signal - there may be no real authentication involved.
Around physical security, I'm often reminded that "locks are for honest thieves".
Anyone can break a window to steal your stuff, getting a duplicate immobilizer chip is hard and usually requires an inside man in a dealer network.
And modern cars absolutely know how to switch safely to a "limp mode" that lets you pull over safely.
Unless you talk to the car's ECUs over the diagnostic port and read out the secret values for creating a duplicate or outright patch out the immobilizer check in the firmware. There's usually no auth on this and it's just obscurity, which I expect to already be broken and exploited by tools available on the black market.
I can't imagine any car would stop if it lost signal with immobilizer chip- that would be a safety problem. That is how relay attacks work- signal is required only for a brief period.
So it's wireless... So someone can still use a relay attack to send the signal from the start button to the keys hanging up by your front door...
The only exception is if I have full control over it, including the ability to lock it down. No OTA updates; if I want to install security patches, it'll be through Ethernet or USB or some other wired connection. But preferably, there wouldn't be a whole lot of software to update in the first place.
That seems to me to be far more secure than a modern tesla.
There's far less chance of leaving your key in the car if you have to press the lock button on the fob after you get out -- done that on hire cars before. The key is always in the same place.
Conversely you can leave the key in the ignition if you're popping into the store to pay for the gas and leaving your passengers in the car. I had a keyless fob on another hire car in my pocket, alarm went off when I went into the store.
I don't get the appeal of keyless.
Many manufacturers have actually worked to improve wireless key security. Including Tesla. But this is a new class of attack on the key fob.
I had a colleague of mine whose BMW was broken into at night. He woke up to police in front of his house (called by BMW's own alert system), there's an atmospheric pressure sensor inside the car and everything.
No sign of the thieves, so he booked an appointment to have the window fixed and didn't think much of it. But then he realized the side panel (in the door column? the column between the front and rear doors) was tweaked over a bit.
The thieves had gone in and cut the cable tree going to the roof of the car, which contains amongst other things the antenna and connection to BMW's alert service. Their plan was to come in the one night, disappear, hope the victim didn't notice that (and the garage doesn't check for it), and come in to steal it for real the next day, or maybe even the same night after the police has gone again.
For Tesla, if they really want they could pry open the frunk and remove the 12V power from the low-voltage battery, then winch the car onto a flatbed. That would disable the GPS tracking and allow access to make money parting out the car. Although not the motors, which are locked to the VCSEC and the owner's configured keys, and bypassing that is still an open problem AFAIK.
Keyless ignition is popular enough with consumers it's likely here to stay.
The last one I heard about was keyless entry systems being abused; thieves carry a briefcase-sized antenna around, amplifying and directing the signal from the car asking the key fob to unlock.
Of course, ideally they want to break into your house and grab the key.
I believe most stolen cars are sent to a "chop shop". There are plenty of useful parts that can be sold. You don't need to start it or worry about someone tracing the vin if you just take untraceable parts off the car.
This is the stance I take when I’m looking at replacing my door locks. I read reviews that talk about the super secure Schlege lock being picked easily and feel like there’s no recourse, until I remember a criminal is more likely to simply put a brick through a window to get in than pick the lock.
When did I say that?