Volkswagen promoted its Fox car to a young audience in Sao Paolo, Brazil, by sponsoring music festival the Planeta Terra Festival - and launching a hunt for 'lost' tickets to the festival via Twitter.

It hid 10 tickets in places throughout Sao Paolo and launched an online platform using Google Maps of the city. To find them, people had to tweet #foxatplanetaterra, and the more tweets, the closer the zoom became on the map. The first one to get to the ticket's location won it. The four-day competition saw the Fox's appearance at Planeta Terra become a trending topic within hours.