I'm a very loyal Auto Zone shopper. I purchased a new car battery almost two years ago and I recently I started having some trouble with it. I brought it back in and they gave me store credit towards a new battery. They removed the old battery, and installed the new one for free. I was out the door for about $50 and thirty or so minutes later. Easy peasy.
A few months ago one of my tail lights went out and after I purchased the new light they installed it as well.
If you are having any issues with your battery or etc they will run a free diagnostic check.