Key PointsTesla posted double-digit year-over-year automotive revenue growth in Q1, but the sales figure is below the total from three years before. The company’s future is highly uncertain, as success relating to autonomous driving and humanoid robots isn’t guaranteed. At Tesla's price-to-earnings ratio exceeding 400, investors have to deal with the steep valuation. These 10 stocks could mint the next wave of millionaires › Looking in the rearv…