Yeah child actor components are the way to go for nesting BP’s inside of BP’s I use this religiously and it’s also great way to make sure there are no dependency overlaps if multiple people are working on the same area. In the example of the car, someone can be working on polishing the wheel components while someone else is working on the body parts without having to stomp on each others work. You can save a lot of time by organizing major components into separate BP’s and the support they have in the editor is pretty solid for this.