Rivian knows there aren't shortcuts to building a successful EV company -- but that doesn't mean it's not taking the road less traveled.If you believe that electric vehicles (EVs) are the future of the automotive industry, as I do, then you've likely spent some time trying to figure out which EV makers to invest in. Is it better to choose an automotive stalwart or opt for an EV start-up with lots of potential upside?You don't have to choose either/or, of course, but if you've got just $500 to invest right n ...