I was watching some videos of live fire AMRAAMs and they all had white vapour trails, they were not thick clouds but they were definitely still visible. I assume that the visibility of these probably depends on the weather but in DCS I never see any smoke coming from the missile even straight after launch. Other missiles have it such as the AIM-7H so I was wondering if they could perhaps include a less dense smoke trail to make it look more like the real thing. This also goes for the AIM-9x for example, on the videos it has a very faint smoke trail I cant remember seeing this in DCS.