Wax and sealants are not going to protect against stone chips, you are in your car doing 70mph, hurtling towards a stone going maybe 50mph in your direction, net speed of 120mph, and a layer of sealant maybe 25 microns (1/40 of a mm) thick. There's only one outcome if that stone has a sharp or pointed edge that hits your car. It's like making a bullet proof vest with single sheet thickness cooking foil.