Vauxhall Astra GTC Infotainment Manual page 52

Selecting tracks using the USB menu
Press the multifunction knob to open
the USB related menu.
To play all tracks in succession:
select Play all.
To display a menu with various
additional options for track search
and selection: select Search.
The search process on the USB
device may take several minutes.
During this time the station last played
will be received.
To play all tracks in random order: set
Shuffle songs (Random) to On.
To repeat the currently played track:
set Repeat to On.
USB port 51