Three years ago I had my alternator replaced by Pep Boys. For a little more money I got the "lifetime" replacement deal which covers the part but not labor.
About a year after i had the work done I needed a new alternator. I took it to Pep Boys and it was replaced for $120 labor.
A couple months ago I started to hear a very loud rattling sound from under the hood. I determined it was the alternator and when I had time took it back to Pep Boys for replacement.
It turned out it was indeed the alternator which cost me another $120 in labor to have replaced.
So far I have paid over $300 in labor for this lifetime warrantee.
Not my idea of a good deal.