Double Loop Dare News Today

>> reporter: wrong. >> six stories high is going to be the biggest double loop ever attempted. >> reporter: mattel, the maker of hot wheels produced the fake documentary to hype the stunt even showing the drastic aftermath of a failed test drive. that was, of course, a joke. >> welcome to this double loop dare. >> reporter: not a joke -- putting the drivers through flight training to familiarize them with the effects of 7 g forces they would feel speeding through the loop. >> not easy, is it? >>...