Just because you can legally get away with shooting someone doesn't mean it is ethically or morally correct.
Most notably, Texas allows the use of deadly force to protect property under some very narrow circumstances. Most other states fall under one of these two definitions. You are allowed to use deadly force to prevent a violent felony, or to prevent serious bodily injury or death. You are allowed to use deadly force in defense of a third party. You have all the rights of the third party, and all of the liabilities of the third party.
As far as shooting someone breaking into your car, no. BUT, if you confront someone breaking into your car, and they then THREATEN you with serious bodily injury or death, you would be justified in protecting yourself. HOWEVER, the DA will look at the totality of the circumstances and perhaps ask why you thought it was a good idea to confront the bad guy. Your life wasn't in danger until you PUT it in danger. You could have done something else, like, call the police. It makes it difficult to say, "I HAD NO CHOICE." You DID have a choice and you CHOSE to escalate the situation to something violent. Not looking good to the DA OR the jury.
Your house is different in most states. In THIS state, if a person enters your home, either by violence or by stealth, with the intent to commit a felony, you can use deadly force. Under most circumstances the fact that they used violence or stealth is regarded as indicative of intent. This is under the long-held philosophy that a man's home is his castle, and may be defended as such. You have a higher level of latitude in your home. This is called the 'castle' doctrine.
You shouldn't be looking for ways to get away with shooting someone. You should be looking for ways to make sure it isn't necessary in the first place.
