John,the average mileage on my cars after 3 years is approx 18-20k miles and the change over costs have been approx 8-10k of course like all cars you can get them cheaper if you go down the ranges the one I drive is the 2nd most expensive model.
For a lot of years Nissan have had a Friends and Family scheme and if you know someone who works there you get a 20% discount off new cars. I am still waiting to have it confirmed to me that Nissan are going to reduce it from September this year