The 2010 Cadillac CTS-V is a true juggernaut, and when at the mercy of the guys at Hennessey Performance, it’s alarming. So alarming that, after pulling .99 longitudinal Gs during the launch of an 11.07-second quarter mile, OnStar was alerted to a possible vehicle emergency.

In the above video, see and hear the Hennessey Cadillac CTS-V700 (indicating its 700 horsepower) record an impressive time, and enjoy the resulting response from OnStar. They’re always so polite.

+ Autoblog: VIDEO: OnStar calls Hennessey after tuned CTS-V pulls .99 g