Renault bought Nissan

Peugeot bought Citroen (or vice versa)

VW also bought Seat, Skoda, Bugatti and Lamborghini

Fiat bought Ferrari (long time ago) which bought Maserati

Fiat also bought Lancia; is Alfa still independent, or did Fiat get them too?

GM owns a big piece of Subaru, and bought Daewoo

Ford owns Mazda