lost my car(Toyota Camry 2011) recently and I am running around the city searching for my car using my spare Remote Key..where I am physically pressing the alarm button to find my car.

I would like to know if there is any tool(that uses my spare Remote key) and automatically detects when I am in close proximity to my car.

(I am looking for a kind of tracking device that Javier Bardem uses,in the movie "No Country for Old Men" to find the money briefcase)