It was a bone stock Viper ACR
It was a bone stock Viper ACR (even street legal tires). They also took a Viper ACR X which is not street legal and it ran a 7:08. There is a detailed article in Sept/Oct issue of Viper magazine. There is also a video I saw in December, but I don't think it has been released yet. The first time out, the record was beat on the third lap so they stopped. The second time out they used the same driver who was now more familiar with the car (he's a Nurenburgring expert). Like I said, if you are concerned about technicalities or proving it wrong, there are plenty of articles out there detailing the event. Good luck.