The 2013 Formula 1 season is drawing to a close this weekend at Sao Paulo, Brazil. There are some who say there is no point watching the rest of the season.The world champion has been crowned already in both the drivers and constructors championships, with Sebastian Vettel and his Red Bull team winning their fourth title in a row. Vettel wrapped up another record with his eighth win in a row at the United States Grand Prix in Austin last weekend. Fernando Alonso also secured second place in the drivers championship in Austin, meaning there is no runner-up spot to fight for either. The quality of racing in 2013 has been lacklustre at times, with a tyre-degradation situation rendering flat-out racing near impossible. It is easy to see why people are tuning out of F1 before the season is done. However, there are still many reasons to watch. It must be remembered that Formula 1 is still the pinnacle of motorsport, and the 22 drivers who make up the grid are considered the best in the world. Despite the racing being slowed down somewhat this year by the Pirelli tyre situation, there are still drivers like Lewis Hamilton who will try to fight for the win. And the motor racing circuit at Sao Paulo is one of the classic races on the calendar, with a rich history of exciting racing. If youre still not convinced, then here are 5 reasons why the Brazilian Grand Prix is a must-see