Like I mentioned in other thread before, use the Tribunal if BMW does not agree to give you a new car.
It is a low cost, nothing to lose (except some of your time) option.
If the tribunal decides you get a new car/full refund, great.
If the tribunal decides the dealer just need to repair it, then you know you have done your best.
Lodge a claim thru the Tribunal.
Porsche 991 Carrera S 2015
Mini R56 JCW 2013
BMW E92 335i 2008