If you believe your Aveo *does* have a block heater, you'd need to:
* Check your owner's manual: It should specify the location if one was installed at the factory or by a previous owner.
* Inspect the engine: Look closely at the engine block itself, particularly near the thermostat housing or lower radiator hose, for a cord and plug. It might be tucked away or hidden by components.
If you can't find a plug, it's highly unlikely your car has a factory-installed block heater.