That's the thing; I think most won't listen to a video like this with sound. At least, I tend to mute videos like this by default. So without the sound, the movement seems unusual. Great car and presentation though, generally!
Do you mean that you have a double sided piece of clothing, and that the weights on one side are different than the back side? quickest way to solve that which I know if is to select by vertex and apply weights by flood fill. Then you can smooth it afterwards if needed. This way you can make a vertex selection in wireframe…
Put HDR image as a background and use default PBR material with "high quality' next yo "perspective" in Max. It's all you need . They did it simple a version ago or so