Very much not the same thing. Your car can't interact with the cars of others without physical contact, and when it does interact, via a crash or otherwise, it would be very obvious to anyone. Even if you were constantly watching the traffic of your phone and other devices, you'll probably miss malicious packets that are sent among the thousands of packets each device sends per minute. It's also not as obvious to recognize what constitutes malicious behavior in your internet device compared to your car.
Also, the operation of the car is simple enough that you can take it to a mechanic for an inspection and they can reliably inspect everything that the car does. There are no hidden behaviors under complex conditions, like crashing into others when there is a full moon or the sky is cloudy. Your devices can do that. If you bring me your phone/laptop/etc and ask me if it's going to send malicious packets to someone somewhen, I can't reliably tell you that it won't. I'm not sure that even if you gathered all software and electronics engineers that supposedly were involved in the construction of your device, they'd be able to provide a reliable answer. I can tell you that it seems like it wouldn't based on initialization files and services, but I can't tell if the function is hidden somehow, like obfuscated in the machine code of the kernel or something. Finding that would require auditing all assembly code running on the machine, which would not be a task for mortals.