The US now imposes a 2.5% tariff on imported passenger cars from the European Union and a 25% tariff on imported pick-up trucks.
Trump has repeatedly singled out German auto imports to the United States for criticism.
In trade wars, there tend to many casualties and few winners.
US President Donald Trump has become fixated on automotive trade, viewing it as a major irritant between the US and its trading partners in Asia and Europe.
The spat is part of a wider tussle over global trade.
Mexico has announced it will, in response, impose tariffs on USA imports, including pork bellies, apples, grapes, cheeses and flat steel, among other products. The tariffs, which had been announced earlier this year, had previously been expected to come into force next month. Tariffs for those materials now stand at 25% in a move to protect local producers.
The Trump administration initially exempted Argentina, Australia, Brazil, Canada, the European Union, Mexico and South Korea from the import duties, but drew criticism for imposing the tariffs on Canada, the European Union and Mexico on June 1.
The initial wave of European Union retaliatory tariffs is aimed at American goods worth €2.8 billion ($3.2 billion).
One of the most frequently discussed items on the E.U.'s list is bourbon, a specialty from the home state of Senate Majority Leader Mitch McConnell (R-Ky.). Most imports come from Asia, but several European brands, including Land Rover, don't have U.S. factories. All told, the $450 billion in potential tariffs would cover almost 90 percent of goods China sends to the United States.
Sales to the USA fell 10 percent to 494,000 vehicles, while Germany automakers produced 804,000 vehicles in the United States previous year. Of those cars, just over half were exported by German vehicle makers.
There could be yet another round of US tariffs. He charged that a succession of poorly negotiated accords - including the North American Free Trade Agreement and the pact that admitted China into the World Trade Organization - put American manufacturers at an unfair disadvantage and destroyed millions of US factory jobs.
The E.U.'s tariffs are not the first retaliation in the escalating global trade war started by the Trump administration: Mexico and China have already launched retaliatory tariffs of their own, while Canada and Japan are soon likely to follow suit.
A Mercedes spokesman has been approached for comment.
The Alliance of Automobile Manufacturers, representing major USA and European automakers, said "tariffs raise vehicle prices ... limit consumer choice and invite retaliatory action by our trading partners.
The requests from four of the seven firms involve Japanese products.
German vehicle makers Volkswagen, Daimler and BMW build vehicles at plants in the US.