I already have one question which concerns the white metal parts, and that's of how do you polish the small parts that bend or break easily? Many of the builds I've seen, the white metal parts seem to be the one area that's the most difficult to finish to the same level as the other mediums in the kit.
What I learned from the Gunze Ferrari I built last year, especially for the bumpers, it takes a few coats of primer, interspersed with sanding, to get a smooth finish. Fortunately, Porsche didn't waste too much time chroming parts so the real challenge will be for the engine frame which is part polished aluminium by the looks of it. Certainly the grain of the white metal is slightly coarser the casting of the original parts, but I think the darker matt colours will probably obscure that.