I have now reset the "Filter" mileage and the "Maintenance Filter" Message is no longer appearing on my display.
I set it for new mileage to 6,000 to be safe, so I do not go over the 12,500. I will have the car serviced in 4 months regardless.
Thanks everyone and apologies for sending out several messages on the same issue, although I do hope this helps other people when the message appears on their vehicles.
FYI: I did speak to the dealer a couple of weeks back and they said to bring the car in for a check which would have cost £90 approx. They also put the frighteners in me when they said it could be the particulate filter needing to be replaced, etc etc etc, quoting me near to 1,000. You would have thought the dealer would know what the message meant straight away. Very disappointing some these dealers.... just trying to take our money.
Non-Technical Nissan QashQai chat. Mk2