https://phys.org/news/2019-01-no-shows-auto-detroit-aim-retool.html

Those brands had been mainstays of the Motor City's celebration of the auto industry, which opens to the public on Saturday. But they are pulling out not just from Detroit but shows worldwide because of a bad date for their vehicle launch cycle, a declining bang for their buck, or bigger buzz from solo events or digital campaigns that go straight to consumers.

In response, auto shows are retooling to remain relevant: moving their events on the calendar or amping up the customer experience by offering test tracks and collecting data on visitors.