Flying car stocks to buy are set to take flight.According to JPMorgan, if flying cars are successful, the market could be worth $1 trillion by 2040. In the best case, by 2040, it could be worth $3 trillion as flying cars get into cargo and military operations. All as dozens of companies — from China to the U.S. and Europe try to get flying cars off the ground.One of the top companies to watch is Joby Aviation (NYSE:JOBY), which moved to the next phase of test flights after completing its pre-production flig ...