Customer called today who has a circle driveway with about 5k sq. ft. inside the circle. They want it power seeded but also want it leveled out. He mows his own lawn and it is a pretty bumpy ride. There are no ruts or holes it's just rough and it is mostly clay. Are there any suggestions on how to smooth this area out maybe in coordination with seeding? If I core aerate, will the cores fill in to smooth it out? Should I consider getting a load of topsoil and spreading it out?