Reply to "What do you think is the next great feature in O scale?"

I thought of a feature that I want to see on Lionel, MTH, and Atlas O modern diesels. If you look at a modern diesel, such as a GEVO or SD70ACe, the bearing caps rotate. Lionel, MTH, and Atlas have the rotating bearing caps on freight cars, and the feature is realistic, but I want the feature on locomotives, too. Scaletrains, a company that makes highly detailed HO and N Scale models, has rotating bearing caps on their modern diesel models.