var zm_data = new Array(
  new Array(1, 'Audi', new Array(
     new Array(1, 'A6')
  )),
  new Array(2, 'Citroën', new Array(
     new Array(1, 'C5'),
     new Array(2, 'C8')
  )),
  new Array(3, 'Ford', new Array(
     new Array(1, 'Transit')
  )),
  new Array(4, 'Mercedes-Benz', new Array(
     new Array(1, 'SL')
  )),
  new Array(5, 'Subaru', new Array(
     new Array(1, 'Forester')
  )),
  new Array(6, 'Volkswagen', new Array(
     new Array(1, 'Touareg')
  ))
)