I have downloaded the manual off the GM website. It explains a very specific set of driving parameters to follow for the first 800km (500mi), along with the engine torque and rpm limitations. After that, and prior to 2,414km (1,500mi) it only states "Do not participate in track events, sport driving schools, or similar activities." I will definitely be following their recommendations. If the rumors are true about blown engines, I'm guessing there may have a been a few impatient guys not following the guidelines and likely revving cold engines to show off for friends. I've read that that break-in procedure is critical with respect to the thin layer of babbit coating the main and con rod bearings.