BMW carried out my first service last week and when I checked the service book, I noticed the mileage recorded was about 400 miles less than the odometer reading. When I asked why, I was told they do a key/fob check for mileage and had I used the spare key for their use. What difference does this make and are they trying to pull the wool over my eyes as a woman motorist? Why don't they take the odometer reading and are there any legal implications here? My car is supplied by Motability.