I get invited to the BMW events at my local dealer all the time. Some of them are worth going to like when they have an M3 you can take out. But normally they are just sales events with no better discounts than you can find elsewhere. The last one I went to promised they would be selling cars at wholesale price plus £100, but this ignored any bonus discount from BMW or BMW finance. If I want to buy a new car, I just bring the best printed quote I can find and ask them to better it, and they do.