Until somebody hacks the system.
I help build semiconductor products for the auto industry. The next generation of electronics is going to have military grade cryptographic security and nasa level safety up and down tie line...from break controllers to engine control.
I own a tesla model 3. I am also a purchaser of full self driving...so I am waiting for them to deliver on the promise. The thing about Tesla..they constantly improve the driver experience. Consider the sentry mode security..something added years after the model S first shipped. No other manufacturer has such a robust car physical security system...and this was a feature added at no additional cost to the fleet.
As for resistance to the vehicle being hacked. It has been done. Tesla was quick to release fixes to the fleet over the air..it will likely happen again..My original point was that the security of vehicles now being taken very seriously by the entire industry.