i use the separate polish and wax. this brings out the shine in the black better than the 2 in 1 polish + wax. i dont understand getting the top wax from megs? i use the normal canaubra wax and after 6 months it still shines like when i first did it. water beading is still the same. obviously swirl marks are apparent but thats what u get for washing it weekly and using it as a daily.
with a white car, you will get away with the 2 in 1 as white isn't as "showy" as the black cars.
i also find that the clay bar after claying it for the first time, isn't really needed. When i clayed my car after the initial 6 months, it didn't have many contaminants. so i might leave it for a full year to see how that goes.
parking it undercover also helps ;)