Thanks to the GMNext blog we have a great video explaining how the record setting run at the Nurburgring by GM's own John Heinricy in a production-spec CTS-V was pulled off:
You certainly haven't seen much in the DrivingEnthusiast network about Cadillac... but that needs to change. Cadillac has it, Cadillac does it. Anybody who tests at the Nurburgring is good in our book.
Note that the defunct SVT organization never tested there... and their absurdly overheating SN95 Cobras never could have survived for a single lap anyway.