Every electronic, smart or dumb, expensive or just a cheapy, they all share one common weakness. To make the long story short, they all need some sort of a power supply to make them function properly.
When its power supplies got cut off, they are dead. To defeated the car thieves from Scrowing you off by using one of these high tech gadget one such as this one mentioning in this article, the most simple and cheapest way to protect your personal properties from thieves is to cut off the power source to your devices.
A simple "relay" that only costs you around $3 at your local hardware store will do just fine.
Get under the daskboard, unscrewed the panel underneath, look for the power line, likely it is the red wire out of the alarm. Connected the red and the white wire to the relay and have the wires run through the panel between the motor and your car interior.
Have those two wires connected to a on/off switch that hide under the hood of your car, or have it hide somewhere else that won't be too noticeable to the car thief that set nearby at the parking garage and watching every single movement of yours and when you reach over to the switch by hand he would not think of you have something more up your sleeves.
You activated your alarm. The alarm is on. The care thief got your code. He was smiling. "Dumb ass.."
You walked around your car and pretenting you are to check up your parking skill "Son of a gun, it's a prefect parking. I am getting better and better every day..." While you were talking to youself like you are some kind of a weird dude. You quickly reach over to the switch and turned the sucker to an off position.
The alarm is now a sitting dead duck without any power source from nowhere. And now, no matter how many times the car chief push his button it will not do a thing. Your car is still yours when you got back.
As for the garage door opener... I do have an idea too, and that is to have a remote on/off desk-top lamp switch you can get one from your local hardware store that cost you less than $10 USD.
What this gadget does is for you to plug that power plug to the wall outlet located on your ceiling 2 feet above your door opener and plug the door opener power to the remote lamp switch. Now the lamp switch is in between your door opener and the outlet on the ceiling.
You got out of your garage. You closed your door. You then shut off the lamp switch through the remote controller provided with the unit. Now, the garage opener is a sitting dead duck also. It won't do nothing until you remotely turned on the lamp switch from outside of the garage before you push the remote door opener. Just don't let the guy who has been sitting not far away from your house and watching know about this lamp switch then you will be okay.
