I use Sonus SFX4 as a sealant and top that with Valet Pro Armetis Wax (which may be unavailable now). They work well together, nice wet/deep finish. I've used Collonite Marque d'elegance before too and although it was good and seemed to last well, I found that it took some flake out of the paintwork (Deep Black). I imagine you wouldn't have that problem on a white car though. NAVIWAX is meant to be very good, it's a bit of minefield asking a question about waxes though as I think everyone will have their own particular favourite.