You can make the argument -- as GM has done -- that by far the most efficient want to achieve 265 miles -- and more -- of range in a car that you will drive in electric mode most of the time, is to use the Volt architecture. Yet, at the same time Tesla has proven that there is a market for a long-range pure EV as well.
There is nothing that is stopping GM from making what is essentially a copy of the Tesla Model S. No, I don't mean an identical copy, but "copy" as in Toyota Camry being a copy of Nissan (NSANY) Altima: Basically, a car that's extremely similar on paper. GM has access to all the technology to do this; they just didn't think a car like that would fly in the marketplace.
If GM simply copied Tesla in this regard, it would inflict what could be a huge blow to Tesla's market cap: Punctuating the scarcity premium. Tesla is valuable, in part, because some investors perceive it doesn't have competition.
I can hear the objections already: GM wouldn't really be able to copy Tesla perfectly, therefore it wouldn't really work, etc. etc. You are missing the point! The point is that as long as GM came out with a high-performance spacious pure EV with at least 265 miles of range, and priced it within striking distance of Tesla, suddenly Tesla's stock market valuation would likely come down a lot.By the way, this goes not only for GM, but for every other car company as well. Surely at least one out all of these giant corporations will be able to cough up a Tesla-competitor within the next few short years? And when that happens... Yes, yes, the arguments against this notion are never-ending: In three to four years, Tesla will have moved on to something better and better, and so forth. That is, again, missing the point. Broadly speaking, the major car companies have access to the necessary technology. Tesla's superior formula was, in part, the focus on the right technology. The other part of the formula, however, was in the keen sense of product definition, just like Apple (AAPL) with the iPad. Tesla saw an opening in the market, and focused all resources on a superior category-killer.