If it's a standard Grundig model, then pressing exp, and scrolling through
the menus to the appropriate item - can't remember which one, too late to go
out now !.  Once found press exp again and the setting will have taken
place.  .........Upon reflection I think 'ign' is the setting you want - to
turn off with ignition.

Have a play - you can always change the settings back again !

Graham

Hi all, my car radio stays on unable to switch off, any help thanks John.