I've leased previous vehicles but none from Nissan. For the most part, the turn-in has been painless if the vehicle is in good shape. I would expect that either Nissan central or your local dealer could provide you with a list of the items that will be examined and what the wear-limits are for each of these. Usually about a month before the "turn-in" the manufacturer will send a professional appraisal to your home or office to examine the vehicle, take pictures and make his/her recommendations. Expect them to look at the obvious things: the condition of exterior body, the wear and tear on the interior and the condition of the tires. The more these things are correct (or at least within normal wear limits) they fewer problems you will have. Personally, I am meticulous about my cars and have always detailed them before the appraisal. Knock on wood, I have not had any issues. In fact, the last two times, the appraiser was literally knocked out by how clean and well maintained the cars appeared. The appraiser will then generally give you a written copy of his/her findings and what needs to be addressed before actually returning the vehicle. Be aware though, the final verdict resides with the manufacturer and will come about a month after your vehicle has undergone a more thorough inspection. So, a word to the wise is sufficient; you really can't hide anything and its best to get any broken items fixed (and save your receipts). I should also mention here that manufacturers vary in their degree of "fussy-ness" about these inspections. Usually luxury brands are more liberal with some not even doing any sort of inspection short of visually seeing that the car came in under its own power and is not wrecked. If you are not leasing another vehicle or if you are leasing one from a different manufacturer, you will be sent a bill for whatever is due and will also be asked to remit your lease termination fee if there is one in your agreement.
If you are going to purchase your leased vehicle, then you will not be subject to any of the above inspections nor a lease termination fee. You will merely be offered some type of financing in accord with whatever the residual value of the the vehicle is as stated in the lease.
However, if you are going to lease another vehicle from the same manufacturer then you have some leverage with respect to any charges that you are assessed. The same is true for any charges stemming from being "over mileage" on your previous lease. These are most often negotiated into your next lease payment or sometimes written off by the dealer.
Disclaimer: This has been a basic overview of my experience. It is not meant to be a definitive guide to leasing. Good luck and may the buyer (lessee) beware!
