The auto industry has been targeted by Donald Trump and is taking the brunt of the slowdown in demand, according to IHS Markit’s latest monthly survey.
Overall manufacturing in the euro area grew the slowest pace in two years in September.
Also, new orders failed to rise for the first time since 2013, Bloomberg reported.
Other European car manufacturers have voiced similar concerns as Markit.
Daimler AG CEO for trucks Martin Daum said in a Bloomberg Television interview on Wednesday: “Trade tensions are a real and true concern for our business because we’re always thinking of long-term cycles.
“We depend on long-term stability.”
It comes amid broader effects as the OECD said this week that global growth may have hit a plateau.
Automakers are Europe’s worst performing sector over the past six months as they are down more than 10 percent.
The French Ambassador to the US also warned that Mr Trump may not be patient enough to undertake long negotiations on trade with the European Union and scrap any possible deal to issue crippling tariffs against the EU28.
Gérard Araud, who has been serving as ambassador in the US since 2014, said there is a strong chance Mr Trump will renew his threat to impose duties on European autos very soon – and may even impose tariffs if he gets fed up with lengthy talks.
He said: “The cars will be certainly a sort of test case in the coming weeks and months on this European-American relationship — if the Americans go back to this idea of tariffs on cars or not.
Explaining talks “will take months to negotiate”, he added: “We are not sure that the president — your president — has the patience to wait for it.
“So the coming months will be critical to whether we have a virtuous negotiation starting between the US and Europe and we forget the threats the tariffs and the trade war, or whether we go back to a trade war with the Europeans.”
The warnings come the same week the US-China trade war deepened.
Beijing said it will retaliate against Mr Trump’s order for more tariffs on its imports.