Hello John:
We ordered a "block heater" option on our 2014. I envisioned an internal element in the oil pan that would be a factory installation, wiring that would be part of the factory looms and have some sort of a cool receptacle panel somewhere, covered by the factory warranty, etc. The heater that we received with our truck is an external element (a flat square) that is roughly adhered to the bottom of the oil pan. The wiring is external (it's run OK) with a simple 3 prong plug wire-tired in a bundle to the frame rail. I'll admit I was a bit disappointed when I first saw it - it looked like something I could have put on myself and the warranty was not part of the Fuso warranty - rather a third party aftermarket warranty. On the other hand I really can't complain about it functionally - we've never used it. So far our FG simply starts up like a champ with a second or two of cranking - although we haven't started her in temperatures less than 15 d F. I don't recall what the option added to the price of our truck but I don't think it was a relatively great amount. Would I order it again now that I know what it consists of? Probably, but I would ask the dealer what he planned to install. If you're looking at a used truck I would not consider the heater we received as something that would encourage a higher offer to the seller.
note added as edit: I forgot that we also received heated mirrors on our truck. I recall that they were part of the standard package that EarthCruiser orders on the trucks that they acquire whereas the block heater was something we requested extra. The heated mirrors appear more like a factory installation - the switch is one of the standard switches in the dash and I think that the heated mirrors are in the owners manual. We've used them rarely, but they worked fine. The only con regarding the mirrors for me is that a section of the wiring from the cab to the mirror is run externally along the bottom arm of the mirror mount. I'd prefer that the wire run inside the arm for a cleaner installation. However, I suspect that running the wire inside the arm could result in pinching the wire when we fold the mirrors in along side the cab for thick brush.
Howard