Though the consumer battery in the 2008 S is in the boot (actually behind the back wall) the place you hook up a trickle battery charger is in the engine compartment. After you remove the bar of black plastic adjacent to the starting battery you will see a brass upright pin. Attach the + clip of the charger to this pin. Then attach the - clip to the negative pole on the charging battery. Your trickle charger will now keep the consumer battery charged.