How To Find Hidden Secret Menu
It is possible to access a secret hidden menu on certain Astra H/Mk5 models. If you have a multi function display then it should be possible.
To access the hidden menu press and hold the BC button on the CD player until you hear a beep (around 9 seconds). You can then scroll through a set of menus by pressing the settings button. Some models require the opposite – hold down the settings button until a beep then press the BC button to scroll through the menu.