Neil Boudette:

The world’s major automakers are sitting on tens of billions of dollars in cash.
 Given the challenges they face, they’re going to need it.
 It’s not just the known challenges, such as meeting stricter regulations in the U.S. and Europe, that threaten to put a strain on their reserves. It’s also the things they don’t yet know: Which technologies will prevail in the marketplace? And how will trends and companies outside the industry influence the pace of progress?