PAX5 -- If you are inclined to code the hitch option yourself, there are other X5 owners on this forum who have done so successfully and would probably be willing to provide some guidance. It is not complicated. I believe I saw in the thread entitled "Coding" that blue dragon coded his own hitch, so you may want to PM him.
Even if your software is not up to date, applying the hitch option works most of the time. You just need to check the trailer brakes afterward to make sure an older module is not preventing the trailer brake lights from operating. If they are working, you are good to go. If not, I know of no workaround. You would have to get your software updated and then re-apply the hitch coding.