Treat the clearcoated wheels like your paint. Except I would never put nu finish on my BMW paint, so I don't use it on my wheels. If the wheels are stained, NU finish will do a good job cleaning them. For newer wheels, stick with the less harsh, non abrasive synthetics. The clear coat on your wheels, is often thinner than the one on your car!! It takes such a small amount of product to coat the wheels, I doubt cost/usage would be an issue with any product.