The problem is that people keep lying to themselves about the definition of the word sentient.
1) Cars use all kind of sensors to collect info about the real world.
They measure how much air is entering the motor in real time. They know if the rear left tire is deflated. They detect when they need to be feed with gas, they know the oil pressure and the ECU, the car's brain, is collecting all this info in real time via its "neurons", the BUS cable.
2) Cars react to this information constantly taking the measures appropriated to assure that the preservation of the car functions.
The ECU sends orders in real time to inject X gas into the motor to match Y liters of air in a perfect mix. The motor enters in panic mode and stops the power temporarily.
3) Cars communicate with their drivers
They send a warning to put more gas, or beep because they detected an obstacle behind them or that the seat belt is not being used.
Cars have lots of sophisticated electric sensors to sense the world so, like amoebas or plum trees, they fit perfectly into the definition of the word sentient
Using sentient as a cheaper synonym of self-conscious is moving the goalposts and a self-scam.