Of course, programming a key fob won't take all day — but it's not a quick fix either. The time required to reprogram these devices depends heavily on factors like the vehicle's make and model ...

It turns out that blank key fobs, sold online, can quickly be programmed to your car. This is a common way for thieves to show up and drive off in just five minutes.

The fob sends a signal to a receiver inside the vehicle that disarms the car’s lock system. Key fobs are part of what is technically known as the vehicle’s remote keyless system, or RKS.

Most of the time, your keys never have to leave your pocket or purse (though if that key is perfect, maybe you'll want it to). Of course, it isn't magic, it's a radio signal coming from your key fob.