Actually, I think you can buy many of the parts for this car in the aftermarket. EVs and EV conversions have been around for a long time and most of these pieces are just off the shelf parts. If the MCU (Motor Control Unit) fails outside of warranty I bet you can get another one for less than what Mitsubishi will sell it to you for. It maybe made by Curtis or Zilla but it will still work.
The Innovative part of this car is not what makes it go, because that is all basic electronic theory. Mitsubishi claims four things that make this car 'innovative': the long wheelbase holding four adult passengers is one of them, the lightweight electric motor and transmission (only 150 lbs for both), the batteries and three way battery charging system. http://www.mitsubishi-motors.com/special/ev/4innovations/index.html
Mitsubishi did everything they could to bring the price down. They claim they have over 40 years of EV development. I have a feeling a few of those parts can be found in their forklifts.
Yet, I feel if the extended warranty gives you the piece of mind that you need to feel comfortable in this car, then its priceless. So I'm just giving you some more information, we won't be left high and dry if Mitsubishi ever decides to pull the plug on the electric car.