How do add a parented object to the new asset browser?

So I have a car model, which consists of multiple seperate objects that are parented to an empy

I would like to add this car to my asset browser… but when I create an asset out of the empty… i can’t add it to my scene with the asset browser… nothing realy happens …

Is this a bug? Or can somebody tell me how to create an asset (for the asset browser) out of an model that consist out of multiple objects. Or am I supposed to clear the empy and join everything together?