Shadow with Lumen not strong enough

Hi, does anybody got an idea how to get darker shadows with Lumen?

Check the lumen scene, make sure distance fields are enabled on the car.

thanks for your response. i´m not sure what i have done wrong, but it seems that this is a problem of objects which i have merged before (almost the entire car) only the wheels aren’t merged. i think the wheels works fine. do you have any idea how to fix it?