The other way is if this stuff becomes easy enough to become a cheap device or an app for your smart phone
Just like script kiddies and other scams, if it's lucrative enough, and easy enough, it'll happen. You don't have to be a high value target. If someone knows they can pop the locks on every Escalade in the parking lot, they're going to do it. And someone might just say "oh, fuck it, let's make all the Corvettes disable their brakes because it will be funny".
If the last decade or so has taught us anything, it's that if it can be hacked, it will be
So you may be unimportant, and nobody is likely to *personally* hack your car... but nothing would prevent a motivated hacker from compiling several exploits for the most commonly driven cars into a single program that any script kiddie can use. And it really won't matter to you whether your car was singled out by a malicious entity, or merely one of thousands, if the brakes and steering are disabled at 60mph.
When people design a platform, one of the first thing they do is make it run code written in C.
Only a limited subset of platforms can run Java, but everything can run C.
All great ideas are controversial, or have been at one time.