1) For a first wash I would definitely do at least a chemical decontamination if not also a mechanical one (e.g., clay bar).
2) I wouldn't assume the paint is flawless. After a thorough wash and decontamination I would inspect the paint and see it is needs any correction, even if it is just in...
I'm going to apply Gtechniq Crystal Serum Light and then Evo on top.
I'm trying to decide which of my compounds/polishes to use to prep the paint before applying the coating.
The paint: New BMW in Portimao Blue
the choices
Megs DA microfiber system D300 compound
or
Dodo Juice Lime Prime...