I just had my headers coated by them about a month ago. Super friendly and helpful people. They know they are charging you for a premium product and give you the support to match the price. If I recall correctly the Lifetime Warranty is they will cover the coating 100% (minus shipping) for the first 2 or 3 years and then any time after that its 50% of the cost of the coating. My headers actually showed up with some flaking around the bolt holes on the flanges. They emailed me a shipping label and when they didn't them in the mail the next day they texted me to make sure I received it since they didnt see the tracking number go live. I got the headers in the mail Tuesday and had them back Saturday. Again, you're paying more than doing them yourself with a rattle can BUT they stand behind their stuff and were great to deal with.
