I currently own a glacier white boxster, my other car is a toyota solara pearl white. my boxster, minimal swirl marks; solara, tons of swirl marks. im on my 16th coatings of zaino wax on the boxster, about 7 coats on my solara. the solara still outshines the boxster. my conclusion is, flat white paint is so hard to bring out the shineness. if our boxster is biarritz white, my guess is, it would be easier to shine the paint work.
I've use meguair's 3 step wax system finishing off with yellow carnauba, good result. however, after claying the boxster then applying the first coat of zaino wax, it already outshined meguiar's. The more you apply the wax, the better it gets. Recently, I've joined PCA concours, I might say (really don't want to toot my own horn)
my glacier white boxster got some attentions due to it's shineness.
p.s. I have no affiliation whatsoever with zaino.
p.s.s. Absolutely no yellowing with zaino wax.