Tesla (TSLA) shares seesawed after the U.S. announced new tariffs on autos. But while the news might seem like a negative for the EV maker, Morningstar's Seth Goldstein thinks otherwise. He believes Tesla's domestic production could give it an edge over competitors like Ford (F) and General Motors (GM), who may struggle to pass on higher costs to consumers. Goldstein also weighs in on Tesla's growth prospects, including the impact of a potential new, more affordable model, and why he thinks the stock's current price might be due for a reality check.