I took my car here two days ago because the 1 year old battery kept dying, it would not start in the rain, and there was a funny sound that may have been the alternator. I figured this was going to cost me money. They worked hard to find my battery warranty as I did not have the receipt. No luck. But they replaced it anyway. I guess I seem honest.
After the battery was replaced, they said that there were no more problems showing up on the diagnostics. And so far, I have not had any problems.
It cost me nothing.
Nice and polite. That deserves 5 stars.