Faraday bag is never explained. Perhaps its presence alone makes the keys easier to find. Didn't someone make a delay switch that would shut down the ignition

Faraday bag is never explained. Perhaps its presence alone makes the keys easier to find. Didn't someone make a delay switch that would shut down the ignition after a few minutes when it was activated? That way, the thief would stall out at some inconvenient point and flee. Faulty memory? Didn't see such a thing in a quick search.