Pretty clever. I never had any problem with mine, but "never" only lasted a year or so with the Europas I've had with stock wheels. A good method of affixing the centers to the wheels is a requirement. I wonder why not glue them on though...
Speaking of wheels, one thing you might not know is that after long service, the lug holes can get wallowed out a bit causing vibration. It might be something for you to think about down the road.