Linux,
If you want to be a good father like you claim you are then you need to gain custody of your kid and put all of this craziness to a complete end so you can get on with giving your child a stable home situation free of abuse (mental and physical). Otherwise, there's just going to be one more psycho running around in the world. Since I might be lucky enough to be alive when said psycho would be of the age where they could do general harm to other law abiding members of our society, including me, I would hold you personally responsible for not taking proper corrective action when you knew you needed to. At this point I'd be giving a s*** about that blue hunk of metal in your driveway and worrying more about the abuse that your child has already had to endure at the hands of it's mother. You child's mother has severe mental deficiencies that can only be corrected by professionals. Beating her senseless or shooting her will only cause you and your child more pain. You need to swiftly collect evidence and present it to the proper authorities.
You've got some work to do:
1) Get a lawyer, a good one. It will cost you short term but pay off long term. They'll tell you exactly what you need to do to manipulate the system properly. It sounds like you go to church search there for someone to help you. Especially if she's exposed herself to the congregation at-large as a little off kilter.
2) Get a video camera, if you don't already have one, that can pick up faces in very low light.
3) At every meeting with her you must have tape rolling and a person to witness. There are people on this board who have stated they will be willing to help you out with this type of thing.
4) Nobody has any proof beyond "he said, she said" at this point on the vandalism, but there is proof of her being an unfit parent. You need to collect even more of that evidenc. If you are willing to sleep in your car to catch her, then you can do it again with video rolling. You might find that having the tape rolling helps conflicts from even starting.
5) You need to distance yourself from the child's mother both physically and emotionally. You should not address her in any personal way and need to treat her as you would any person on the street that you do not know . Do not be familiar or glib. Be very careful of the things you say and do not show emotion.
6) Get a punching bag and securely attach it to something. You'll take out all of those emotions that you would normally unleash upon her in the form of words or actions on the bag. You'll feel better after punching it for about thrity minutes and it's a great workout. Try to eat well and get plenty of sleep. Now is a time when you need to be mentally alert and focused.
Hope this advice helps. I certainly never thought I'd be getting in any way interested or involved in a discussion such as this on a board such as this. But I feel compelled because I fear that a child is in danger. Additionally, I fear the frequent false bravado and posturing that Alpha males such as us display on a regular basis is clouding the issues, and advice being given, in this case and at this point the only solution is to turn the whole thing over to the authorities to properly serve the child, the affected parties and society in general residing in Arlington, Texas.
It's sad really, but I suspect that the mother in this case was also abused mentally and physically as a child which has lead her to being the way she is today. I sincerely hope, but unfortunately doubt, that she has contained her physical abuse to inanimate objects. And Linux, without being too personal, I fear you too may have some things to work out so that you can be sure to avoid such poor relationships in the future.
Good Luck, you need it!