President Trump's tariffs could cause car prices to increase by as much as $12,000.If tariffs stay in place, sticker prices could skyrocket and some car models could disappear from showrooms.The automobile industry could experience a historic decrease in production, up to a third of the output in the US, Canada, and Mexico.On average, the list price of new vehicles in the US could increase by over 7% due to tariffs and other factors.