Tesla Motors (NASDAQ:TSLA) stock is down since reporting earnings, but fundamentally nothing has changed about the company. In fact, it's investors who got ahead of themselves in valuing this stock. 

The true challenges for Tesla come in the next few years as other automakers introduce increasingly competitive vehicles. Ford (NYSE:F) is betting that its Focus Electric can give it a foothold in the market and Nissan and GM have eyes on the electric vehicle space as well. But the biggest competition may be coming from Germany, where BMW's i8 is being developed with specs that can match the performance of the Model S in many ways. If BMW can get it right, then Tesla's monopoly on high-performance EVs will be over. 

Erin Miller sat down with Motley Fool contributor Travis Hoium to hear just what investors should be watching for in the future.

Erin Miller has no position in any stocks mentioned. Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool recommends BMW, Ford, General Motors, and Tesla Motors. The Motley Fool owns shares of Ford and Tesla Motors. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.