It's not really a lifetime warranty though. If you click through to the Tesla purchasing page, there is (only) a 30 years Power Warranty and Weatherization Warranty... which in my mind renders calling it a lifetime warranty sort of silly, as the purpose of the shingles (power generation) is not covered by the lifetime portion of the warranty. 30 years still seems like a significant warranty for a product like this though.
The odds that Tesla will be around and willing to honor their warranty 25 years from now are also nowhere near 100%. Also, if you read the fine print, you will notice that the warranty will not cover the most frequent cause of roof problems - leaks in the seams.
The same can be said for your local fly-by-night roofer, but it sounds like you can buy two roofs for the price of a SolarRoof.
Also, another thing to be concerned about is whether or not you're going to be stuck in the middle of a pass-the-blame around football match between Tesla, and their subcontractors. (I guarantee you that the people installing your roof will not be Tesla employees.) In roofs, installation mistakes can cost you dearly - they are the primary cause of roof problems.
You can readily buy a 30 year shingle roof. Calling it a lifetime warranty when it is no better than a common, good quality shingle roof is absurd. Metal roofs have even longer warranties.
