McLaren team principal Martin Whitmarsh, pictured here in 2011, has warned the United States will prove a much tougher nut to crack than Asia as Formula One prepares for its latest bid to win over the... more 

McLaren team principal Martin Whitmarsh, pictured here in 2011, has warned the United States will prove a much tougher nut to crack than Asia as Formula One prepares for its latest bid to win over the huge potential market less