I understand your desire to approach this problem in the way you currently are. But I do not think it is the right way to solve the problem at all. She could simply get a replacement iPhone and be back to her texting ways, she could use a friend’s phone, she could even get a phone which is MORE distracting. I strongly believe the solution to this problem lies in communicating with your daughter just how concerned you are about her texting while driving, showing her studies that demonstrate how texting is worse than drinking and driving, etc. You can also approach this issue as a requirement for accessing the car – make a condition that she can only use the car if she leaves her phone turned off in the glove compartment while she is driving. The reason I discourage your attempts to sabotage the phone is twofold. First off, you are just throwing your own money away by breaking the iPhone. But the real reason is that with technology, the solution is never in limiting or denying access to technology, kids are smart and they can get around blocks or limits. If you truly want to have peace of mind, you need to feel confident in her judgment of not texting while driving, and this requires solving the problem with communication rather than with technological limits. All parents have worries when their children start driving. My dad sure did, and made no attempts to hide his concern at all. It’s simply one of the first steps in becoming an adult.