Let's look at the car model, there are people selling chips to replace the EPROM in the cars ECM to deliver more horsepower. This will most certainly void your warranty, it may even cause you to fail an EPA test if your state mandates that. Or let's say I disconnect the sensor on the transmission so I can bypass the redline fuel cutoff, think that won't void warranty and potentially kill the car?? Apple is referring to the fact that many of these hacks modify the firmware which is NOT restored if you revert your iPhone. They are saying that they will not be held accountable for someone modifying the iPhone. A coworker once drove his car over 30K miles without changing/adding oil. After the check engine light came on with the oil pressure light, he simply drove on until the motor died..couldn't understand why there was no warranty offered...