* Dacia: A Romanian car brand.
* Daihatsu: A Japanese car manufacturer (mostly known for smaller cars).
* Dodge: An American car brand known for muscle cars and trucks.
* DeLorean: Famous for the DMC-12, a gull-winged sports car.
* DS: A French premium car brand (a spin-off from Citroën).
* Daewoo: A South Korean car manufacturer (largely defunct, now mostly represented by Chevrolet).
This list isn't exhaustive, as there have been many models and less-known brands with names beginning with "D" throughout automotive history.