Wallet. Cell phone. Car keys. That’s the mental checklist many of us go through before we leave the house. But don’t you hate it when you approach your car, click the unlock button and nothing happens ...

The days of replacing a car key by having an inexpensive ... Yu says. The inside of a Chevy key fob swapped into this aftermarket shell: Battery (left), circuitry (middle), uncut backup key (right).