Here's how GM could beat Tesla, along with why it won't happen. GM could just take a look at what Tesla is doing, and do all of the same things, then do certain key things better. From a sheer resources and capability standpoint, GM could beat the pants off of Tesla. I think Tesla is counting on: 1) GM and other big automakers being too set in their ways and 2) GM and other big automakers getting some key things very, very wrong. Security is probably a key example.
It's an oft-cited insurgency move to use the big power's culture against itself.