Custom car locator

Goodmorning everyone.
It states that the idea of ​​the locator had abandoned long ago, but I came back in the lead yesterday after talking with a friend to whom they stole (yesterday) the car under the house. Parked in a fairly well-traveled street in the midst of many other machines. The car was not even new, an Audi A3 11/12 years of age.

Searching the internet I saw that there are many trackers for cars, but almost all of them work by relying on pay sites, and no one has all that I wish he had.

Below I list everything that I would like did the locator:

  • In reception of a specific message and / or a call from one or more specific numbers, send his location with an SMS message and / or to a specific Internet site;
  • Self-powered, as if the thieves off the battery should be able to operate the same. I thought of a mobile battery or battery pack. The charge would be done through the car battery when it is in motion;
  • Module for saving data to SD at periodic intervals when the car is in motion (this is my personal whim, but that obviously goes a bit 'over the main functionality);
  • Everything should be able to stay in stand-by mode when the machine is off, but always be ready to do his duty in case of need. For the SIM module guess this thing is not possible, but I think with a battery of adequate size, or managing the connection to the operator to intelligently (perhaps by delaying the connection on and off) you could save a bit 'of battery ;
  • Accuracy of decent GPS data. I do not say centimeter but at least a dozen meters. If you are unable to receive the GPS location (eg. They have closed the car in a garage and are sharpening the knife to disassemble) groped to find the location via cell phone.

I think this is all over.

Now I rely on you for ideas and comments, feasibility and whatnot.

I know what I should do, but I'm not able to do the shopping list of the various materials necessary for the realization.

Thank you all in advance and sorry for my english (I used google translate :-[ ),
Tiziano

Yep.

An old iPhone with the "find my phone" enabled. Will save you the hassle and time.