The 1970 Porsche 917K driven by Steve McQueen in the classic film 'Le Mans' will be put up for auction next month - and could fetch more than $18million. Expected to become the most expensive Porsche ever, the car is one of racing's most illustrious vehicles having competed in the race and starred with McQueen in the movie. McQueen even drove it while crossing the finishing line in the winning shot. The sports car represents the culmination of Porsche's engineering at the time as the company sought to take its first victory at the 1970 race, according to the auction's...