Visitors walk past vintage and classic cars displayed by Bonhams auction house, during an exhibition, at the Grand Palais in Paris, Wednesday, February 4, 2015. The Grand Palais is staging an exhibition of vintage cars, to be followed by a sale of historic cars by Bonhams auction house on Thursday. (Photo by Jacques Brinon/AP Photo)

The pit lane is reflected in the visor of a Mercedes Formula One pit crew member during the second practice session of the Australian F1 Grand Prix at the Albert Park circuit in Melbourne March 13, 2015. REUTERS/Brandon Malone

Mercedes driver Nico Rosberg, right, of Germany steers his car in front of Mercedes driver Mercedes driver Lewis Hamilton of Britain, center and Ferrari driver Sebastian Vettel of Germany during the Austrian Formula One Grand Prix race at the Red Bull Ring in Spielberg, southern Austria, Sunday, June 21, 2015. (AP Photo/Kerstin Joensson)

Mr. Olympia Phil Heath poses during a media call ahead of the 2012 IFBB Australian Pro Grand Prix XIII on March 16, 2012 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

American free climber Dean Potter walks on a 41-meter-long and two-centimeter-wide slackline over Enshi Grand Canyon at an altitude of 1,800m on April 22, 2012 in Enshi, Hubei Province of China. Potter successfully finished the lone slackline walk in about three minutes without taking any protective measures. (Photo by ChinaFotoPress/ChinaFotoPress)