Does anyone know the life span of Wolfs Glass guard? It working fine on some surfaces but has lost its touch on others. I am also looking to replace with nanolex glass sealant this time around but dont know if that is possible without removing the Wolfs. Any thoughts on if that is possible / how to do it since that are both nano products? Just a clay / polish? Thanks! Details. Glass Guard applied about 4 year ago but not on a daily driver. Only about 15,000 miles since application.