When I turn on the ignition key now, nothing happens. Battery check shows 4.6 volts (?). The last things that happened before this: 1) Bell dinged when removing key from ignition. 2) When trying to restart, airbag light showed on dashboard. 3) When trying to restart, electric trunk release actuator clicked several times.
Turn Ignition key - Nothing on 2005 Chevrolet Malibu
4.6 volts is too low to start the car. The battery's age makes it likely that you need a new battery. Turn on the ignition switch to the on but not run position do you see an icon on the instrument panel representing a battery, if you do not see this battery icon the alternator is not seeing power to allow it to charge. Start the engine does the battery icon go out. Put a volt meter across the battery terminals with the engine off, at rest the battery voltage should be 12.6 volts if the battery is fully charged. Now get a friend to start the car while you watch the voltmeter, the voltage reading across the battery should read approximately 14.6 volts if the alternator is charging correctly.