Editable Car/Plane?

I am new to Unity and I am trying to make a game where you place blocks to make your plane and can add jets/weapons but I will get to that later. I am wondering if there is any way to get separate blocks that you place during the game into one prefab or something that i can add as a plane/car that i can control. I already have a plane control script so all I need is how to substitute the plane I have now for whatever array of blocks the player places.

• Thanks for any help