Porsche and Volvo were the only brands that saw their registrations rise in June. Porsche sales rose 7.5 percent while Volvo gained 0.2 percent.
Volkswagen Group registrations dropped by 26 percent with Seat sales down 35 percent, VW brand down 29 percent, Audi down 27 percent and Skoda down 13 percent.
Renault Group sales fell 16 percent, with Renault down 15 percent and Dacia registrations down 18 percent.
PSA Group sales dropped by 30 percent, with Opel down 48 percent, Citroen down 23 percent and Peugeot down 17 percent.
Luxury automakers also posted a drop in June, with BMW Group's sales falling 26 percent. Both the BMW and Mini brands were down 26 percent.
Rival Daimler's registrations dropped19 percent as Mercedes-Benz fell 12 percent and Smart sales plunged 83 percent.
Among Asian brands, Hyundai and Kia both fell 27 percent, Nissan was down 30 percent and Toyota dropped 14 percent.
- Download PDF here for European registrations by brand in June.
Fiat brand sales dropped 26 percent, while Alfa Romeo registrations fell 38 percent.
Ford was down 25 percent, Land Rover 35 percent and Jaguar 58 percent.
Sales fell in all European markets except France where they rose 1.2 percent in June thanks to government incentives for low-emissions vehicles that were introduced at the beginning of the month.
Registrations in Germany tumbled 32 percent and slumped in Spain, Italy and Portugal with drops of 37 percent, 23 percent and 56 percent respectively.
Through June, overall European sales fell 40 percent to 8.43 million, ACEA said.