God, I hate these articles. They give some really smart dudes some grant money and all the time they need to hack the shit out of something. The situations are so ideal it's completely unrealistic to expect this to happen to you. These articles have been running for 6-8 years now, yet I know of no case of it actually happening in the real world.
It's a real potential problem, but if you really understood a little about vehicle software/network systems you'd know how incredibly difficult is to, say, turn off someone's stereo by hacking through the TPMS...it just doesn't make sense. Instead of hacking remotely, hack locally. Just get ahold of the key and do whatever the hell you want with the car...which is what these guys did.