Getty Kyle Busch and Greg Biffle stand in the garage area during practice for the NASCAR Sprint Cup Series race at New Hampshire Motor Speedway in Loudon, New Hampshire, in July 2015. For longtime NASCAR fans , the loss of Kyle Busch still doesn’t feel real. And for many across the sport, it has made another painful reality impossible to ignore: NASCAR is now mourning two of its biggest stars in less than six months. Less than six months ago, the NASCAR world was rocked by the death of Greg