Prestige wishes to advise the following. That all metals will expand and contract at different rates. This expansion can and will move adhesives overtime and can result in a natural wave to a metal materials. This is not a defect but a natural occurrence when working with sheet metal. Prestige will work to the closest of tolerance but reserves the right to a margin of 2.5mm tolerance on products and services provided. Prestige can not warrant nor accept any responsibility on any product once removed from the main premises of prestige for external treatment or other applications out side of the original manufactured state, not limited to the unknown use of products after purchase.