Opel INSIGNIA Owner's Manual page 51

Seat positioning
Pull handle, slide seat, release
handle. Try to move the seat back and
forth to ensure that the seat is locked
in place.
Seat backrests
Pull lever, adjust inclination and
release lever. Allow the backrest to
engage audibly.
Seats, restraints
Seat height
Press switch
top = seat higher
bottom = seat lower
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