Personally, I generally wash my vehicles prior to adding additional protectant ( sealant or wax). This step will remove any QD, including QS and FD, that was present on the finish. The only exception would be when my Z28 is inhiberation and I just dust off (Cali duster) and QD with Z6 and apply additional coat(s). None of my EX or carnauba ( Souveran and P21S) vehicles are hiberated ( daily drivers) so a wash is alway the first step. :wavey