(FOX 2) - President Donald Trump took to Twitter last week to speak about illegal Mexican immigration.
"Next step is to close the border," he wrote.
Those are seven words that have the potential to shut auto makers down in seven days.
"It would shut down every assembly plant. automotive assembly plant within a week," said John C. Taylor, Wayne State department of marketing.
And for that very reason, auto experts are having a hard time seeing this as a reality.
"There are a lot of suppliers on the Mexican side of the border," said Jeff Gilbert, WWJ 950 auto reporter. "In fact just about every vehicle made today has some sort of Mexican content."
"Thirteen percent of the parts in US Assembly Plants are coming from Mexico. You miss one bolt, basically, and you are done," Taylor said.
Vehicles today come with so much built in technology - from back up cameras to plug and play phone accessories. Everything under the hood comes with investment in research and development and recoup that you got to think globally which makes selling goods across borders so valuable to the bottom line.
"It's not going to happen when you have a very limited market to sell too."
Part of the reason the effect of a border closing would be felt so quickly has to do with a lack of inventory when it comes to auto parts.
"It is too expensive to sit on billions of dollars in inventory," Taylor said. "You shut down those assembly plants and it will cost about $4 billion to $5 billion a week."
Still, President Donald Trump not mincing words when it comes to this issue.
"If Mexico doesn't immediately stop all illegal immigration coming into the United States from our southern border I will be closing," he tweeted. And while his exact plan is unknown, there is a strategy to get help in their fight against illegal border crossing.
"To get some concessions out of the Central American and Mexican government to stem the flow a little bit," Taylor said.
Auto makers appear to be taking a wait and see approach before reacting one way or another.