I would think that it has Either a broken wire in the engine bay Near the Starter motor as suggested, OR it may have a Faulty instrument panel. It is unlikely for a late model VW to have a Bulb for the warning light, I would expect it to be LED's built into the cluster. But the theory is still the same that the alternator needs to see the light working otherwise you will have to rev its nuts off to make it charge. Tony.