These are 11" parts. Disc hub sticks out further on one side, this side goes to the rear. Place the disc on the flywheel backwards with bolts installed and spinning it finds the springs of the disc hitting the bolt heads. Disc will not lay down flat on the flywheel. Can't imagine the noise this would cause, and destroy the hub in seconds.

Why the sticker? To reduce warranty claims and reduce calls to the tech line.

It all seems so easy on the bench, but laying under the car cold and wet can cause many problems.