Repellent has to be faced upwards (slightly tilted) to re-bounce the ultrasonic sound throughout the engine bay. Wires to be connected to the battery terminals has highlighted in the above picture.
Stick the aluminium foil sheet just opposite to the repeller to re-bounce the ultrasonic sound. 
IMPORTANT NOTE: Skoda may require double repellent installation, as the engine compartment is too congested to distribute the ultrasonic sound throughout the bonnet area. Please see double repellent Installation