Car Cargo Carrier alarm


Damn - had my whole car cargo carrier lifted off my car, so on the hunt for solution for next time.
(seems they snipped the 4 clams hosted on the roof-rack instead of using the key-lock. So much for Thule good qlty products).

Looking at suggestions as I am looking to create a some device (sensor or even GPS tracker) connected via some bluetooth to a car alarm unit (planned to get also) to trigger alerts and car siren.

The idea is to leverage the planned existing car alarm & siren so not too much in carrier above the car. I do prefer a low cost GPS tracker in the carrier as this way I can track the pricks if it happens again (maybe add a 2nd GPS tracker in car too for safety/tracking of car) .

So should I pursue to get some specific alarm that has open interfaces to work with this ‘extra’ wireless bluetooth GPS tracker in carrier and when bluetooth signal is lost from being in carrier to trigger an alarm (issue would be with false alarm if GPS tracker losses power so looking at a long lasting battery option with CAT-M (for GSM SIM) tech but the BT will drain it still. Options here?

If the event does happen, would need the tracking option which I would assume will come from the GPS tracker or service.

That is my idea, more to come but thought would reach out to this community for some suggestions on parts and feedback.

Appreciate any feedback.


I expect this will be more difficult than you expect. What you need to be useful is a gps receiver and a cellular interface (both of which have Fritzing parts available) along with a power source hidden (as I expect thieves to be smart enough to check for such things to avoid getting caught) but with access to the sky for the gps position and cellular service which isn’t likely to be easy to provide (especially when it needs to remain hidden.) You would likely need a connection to the car battery to keep the internal battery for the gps/cell charged which in turn would make it obvious there was an anti theft device present to be found and removed. As well there is the cost of the cellular connection (presumably an ongoing cost) that would allow access to the gps data once the carrier is stolen (assuming the tracker doesn’t get found.) I suspect the cost of this may be more than it is worth.