Thanks for the reply. I use virtually nothing but BP Premium. 12500+ miles. I am not comparing long and short trips, only like useage. Some weeks or days it will perform great and the next day the mileage goes to hell even though the conditions are the same or even better. The nav/associated functions quit the 2nd day i had the car. took them 2 days to fix it, so this is not a new issue. i want to know why it is not storing faults with all the failures it has. The garage door opener functions about half of the time but they forgot to add it to the list. anyway i have a very good relationship with the dealer as we have have bought somewhere between 12 and 20 BMWs.