I can they will all be 2004 audio and physicsGood clarification on the Viper gearbox - I spotted it was a h-shifter in the Barcelona video, but later in the vid there is another Viper with a sequential (I think).
Also, the reason for the 2005 aero on the 550 is for two reasons - 1; I prefer the shapely nature of it, but more importantly 2; I have much better reference images for that spec, so its a lot easier to model.
Pretty sure physics wise it will be the earlier 2004 spec, but I can't say that with any certainty.