Massive competition from many established companies, $300M+ tooling costs to roll out a new car, low profit margins, high marketing costs, long sales cycles, etc... Auto manufactuing is a bad business to be in, maybe second only to operating airlines. And Tesla owns no special ip on their battery tech, they will likely have to do a lot of dilution in the future to stay alive. That said, I wish them luck, and if anyone can do it, it's Elon Musk.