I've had mine 12 years and the interior is as new... all the similar ones with leather started to show wear at about year 4...
2002 BMW 325iT with black Naugahyde interior... funny thing is everyone thinks it's leather... even when it was brand new and I was driving it in Germany.
Definitely right on few keeping high end cars past the warranty... no one I work with has kept a 12 cylinder BMW or Mercedes past the warranty and that goes for the Alpina b7, Cadillac STS and Porsche... most of the Docs simply lease.
I've seen a lot of pretty worn leather driver's seats. Leather house furniture seems to stand up OK, so perhaps it is just people not keeping the leather conditioned adequately, and the UV and heat taking it's toll. Back to that lease/dump/why bother concept....
I prefer a good quality cloth for personal vehicles (partly for cold/heat, w/o getting into fancy HVAC), but leather or naugahyde has the advantage of being easier to slide across - helpful for an elderly person with diminished strength.
I have to go back and check, do we have any pics or links for Brian's truck yet ?
Rgds, D.