First thing's first, this car uses a ton of different textures and materials than any other car and the model itself has some nasty gaps letting you see through it, so those are a couple reasons why I originally did not add it myself. However, as BMW starts with a "B" though, it is near the top of the list as I slowly make my way through fixing vehicle materials and textures on occasion.
That all being said though, I don't know how any of the changes I made would have caused it to be any different now, but maybe I'll find out when I get to it. I'll likely have it done by next weekend. So if it's still an issue after that, it sounds like you might have conflicts on your end, like having TDM's content or workshop addon in addition to PH content.