First: don't listen to people who are saying "it would take a whole team to do it" or "it would take years". They don't know what they're talking about. However, it's really not that necessary of an upgrade other than some nice extra feature that could be thrown in. Unless a newer version of TGE fixes the whole vehicle collision being stuff, we don't need it.
Second: These things cost money, as it has already been said, so it probably won't happen unless 100% necessary.