Toyota models appeared 53 times in the top 10 rankings of 30 European markets through five months.
Kia pulled ahead of Skoda 29 to 28 in May. In April the brands were tied as 29.
Volkswagen brand also had 28 appearance, tying its Czech sibling, after having 25 in April.
Dacia had 22 placements, while Hyundai and Peugeot ended the month with 20, according to figures from market researcher Dataforce.
The best individual model was the Toyota Corolla with 13 top-10 finishes through five months, with No. 1s in Bulgaria, Finland and Poland.