A Bentley showroom in Mayfair was also affected by the action from the climate group.
Police have arrested two people on suspicion of criminal damage following the protest on Wednesday morning.
Just Stop Oil has promised to protest every day this month in a call to end new oil and gas licenses.
Have you been affected by Just Stop Oil’s actions? Contact firstname.lastname@example.org
So far this month, protesters have smeared cake in the face of a King Charles III waxwork, climbed up a bridge over the Thames and glued themselves to roads in central London.
Just Stop Oil shared a video of activists spraying orange paint over luxury car dealers in the capital on Wednesday morning.
It said two supporters had targeted showrooms in Berkeley Square and Bruton Street in Mayfair.
The climate group said they sprayed paint over HR Owen Bugatti, Jack Barclay Bentley, Bentley Motor Cars London and Ferrari Mayfair.
The activists made a speech outside the showrooms after they had finished spraying paint over them.
“In what world is it OK to be buying and selling luxury cars when people can’t even afford to eat or heat their homes and when people all over the world are suffering and dying because of the devastating impacts of the climate crisis,” one said.
“The government needs to step up. Inequality is what is driving the climate crisis.”
The Metropolitan Police said: “Protestors have sprayed paint at the Ferrari and Bentley garages in Berkley Square at 8.39am.”
It said officers were “rapidly on scene” and arrested two people for criminal damage.
“They have been taken into custody to a central London police station,” the Met added.
On Tuesday, Just Stop Oil activists threw paint over influential fossil fuel lobbying headquarters in London.
🧡 BREAKING: LUXURY CAR DEALERSHIPS PAINTED ORANGE
🚗 At 8:30am today, two Just Stop Oil supporters sprayed orange paint over several luxury car dealers on Berkeley Sq and Bruton St, including HR Owen Bugatti, Jack Barclay Bentley, Bentley Motor Cars London and Ferrari Mayfair pic.twitter.com/gZhjIQDedw
— Just Stop Oil ⚖️💀🛢 (@JustStop_Oil) October 26, 2022
The day before, activists were arrested after throwing chocolate cake in the face of a waxwork statue of the king at Madame Tussauds.
Other action this month has included throwing tomato soup over a Van Gogh masterpiece, blocking the Abbey Road crossing and spraying paint over Harrods and the New Scotland Yard sign at the Metropolitan Police HQ.
Just Stop Oil has vowed to continue its protests until the government meets its demand to halt all new oil and gas licenses.