You can try to just extend the time for another year, keep the mileage at 100k. I paid about R4.5k to do that on my Z4, but it had lower km's when the 5 years were up (~85k km).
I did not extend the MP on my X5, even at R24k it was too much. I'd rather keep the money in my own account and spend it when necessary, than give it to BMW to keep and nothing breaks in the year.
What could go wrong in 5000km?
The only argument for possibly extending is if you are planning to sell the car within the next year. Even then, will it command a R38k premium over another car with no MP when you trade it in?:dunno: