I've bought every car I ever owned from Karl's.
A couple quick stories....
My first car ever, an 82' Camaro, blows the engine one day, cracked block. Way out of warranty. I have it towed to Karl's to diagnose. They pull the engine and call me to come down. I get there and the guy shows me the broken crank shaft and the big air bubble in the middle of it right where it cracked. Tells me it was a manufacturing defect and they'll take care of it and bill Chevy, even though it's out of warranty. A week later brand new engine... no bill. Amazing. Would have been easy to just sell me an engine or another car, I would have never known.
A couple years ago my wife's Malibu had an issue with the AC.. it would work and then stop occasionally. We brought it in several times but they couldn't re-create it and had replaced the easy stuff but it kept happening. While this was going on the warranty expired. One day my wife was picking it up for the 5th or 6th time and it stopped working again before it was out of the lot. She lost it (I wasn't with) she went back in and asked to see Karl. She got in to see him in about 15 minutes and was telling him the story and started crying because she was so frustrated. He called a tech in and told him to replace every part that could possibly touch or affect the AC.... Including the wiring harness throughout the car and he wanted it back to us the next day. No charge. Also gave her a loaner car for the day. Haven't had an issue with it since.
Their dealer for life slogan may be corny but their actions have made it true for me.