Update: I've had the car for over a year now with no problems; this used car has been great although no basic maintenance seems to have been performed before it was sold to me.
Review from a year ago: Suspicious. Bought a used car. One of the selling points was a Hendrick Certified Warranty which was supposed to guarantee the powertrain for 10yr/100,000 miles +more. They did not give me any documentation of a warranty. One of the documents we signed closing the deal stated that unless we received a written warranty within 90 days, there would be no warranty. I called, texted, emailed, talked to 3 different people who all gave excuses, went down there in person, waited over 2 hours and received every excuse in the book --all with big smiles on their faces. "Oh it's in your glove box!" No. "Oh, it's in the envelope with your other documents." No. "I'll email it to you". Didn't. "I'll mail it to you." Didn't. "You don't need the warranty. Just bring your car in, and we'll honor it. It's on the website." Not believing it.