Lets talk about models - Tesla doesnt make a mass market car - even their basic sedan, starts at 35k - I can buy a nicely equipped Taurus, Fusion, Malibu , Impala, Camry or Avalon for less than that - and from a size perspective its far closer to a Prius or Volt (23k or 33k starting respectively).
Secondly, Brand Cachet - Tesla appears to be positioning itself from a branding perspective closer to where BMW or Audi does.
I'm more hopeful for Ford figuring out technology, than I am with Tesla figuring out how to be a really good mass market car company.
The reason I consider Tesla overvalued has to do with potential market share, as well as the traditional margin on cars - if they try to be a mass market manufacturer, I don't see Tesla capturing more than 10% of the (very crowded) marketplace nor do I see them easily besting the historic 5% margin most (mass market) automakers have, if they decide to be more like BMW or Audi - their margin could go up by a rather large amount - but their volume would go down by an almost an large amount... they might however have a bright future as a technology licensing company - that remains to be seen.
In short however, if you measure it by the "car company yardstick" its drastically over overvalued - if you measure it by the "technology company yardstick" however the numbers start to look a little friendlier. Consider though that the technology company yardstick seems to be mostly based on hype, rather than actualized returns basis.
Consider for a moment that Tesla isnt pioneering a new market here, it's trying to produce a better dohicky (thats really cool, but not revolutionary) in an already crowded market - this alone says that the technology yardstick shouldn't apply - you should instead measure it like its peers in that industry.