Actually as luck would have it, Piazza Nissan of Ardmore, on 08/02/2022 did some work on vehicle VIN No.: JN8AZ1MW4DW301652. The work required the car to be put on a lift and the charge was for $1238.50.
On the Invoice 236055, Item B , Health Check, MPI, "Perform Nissan’s 27 point vehicle inspection." Nissan’s Complimentary Multi-Point Inspection (CMPI). There are six categories to the CMPI.
The third category is titled UNDER VEHICLE. The first item is Rear Shocks/Rear Subframe/ Suspension.
I was talking with a friend of mine, a retired corp. lawyer that I've requested help from in the past. He was looking at your issue from Nissan's point of view and how they'd react.
The first question that he had was: "What was the miles between 8/02/22 when serviced by Nissan and when it failed."
The less the miles, the better. If it's under 1k, then it's a no brainer that the check list was not performed.
Several take-aways from his conversation.
First, Nissan as a corporation will involve legal as soon as they get a official "Notice of Discovery" from a lawyer. Needed from them will the tech's signoff, any written/video pertaining to the 27-point inspection training.
Guess what, Universal Nissan has a training video used for new techs. It's posted on YouTube!
Nissan Service: Multi Point Inspection - YouTube
2:35 - 2:40 First tech states that the other tech was doing an underbody inspection. You can see the other tech moving from the back towards the front driver's side suspension and starting to check it with a light wand.
If your tech had inspected the rear suspension in this manner, then he would have surely seen the excessively rusted suspension part and should have checked the inspection report with that information so it could be passed to the customer.
Second is that all that is really needed to win is the "Notice of Discover" letter sent asking for the tech's signoff, written/video of training, and any shop camera surveillance video pertaining to your vehicle's repair.
With the letter also describing the danger of failure at highway speeds, possibly causing the vehicle to overturn and flip causing serious injury to the occupants, and photos of the rusted part and failure. Also, that you as the owner rely on the dealer to be truthful with their inspection report to notify you of any potential driving safety issues.
After research on their part, they will probably see it as a no-win situation and offer a settlement.
Third, the thing about a tech required to report imminent failure of a part that can cause a car to lose control and crash? Seems that it's stood up in court, even though there no written law. In other words, there's been case precedent resolving this issue.
He said any lawyer can write up a letter in this manner for a flat fee, usually about $500, with the understanding that they will be called if it comes to legal action.
Take everything written here at face value. As he said, no two cases are the same, similar, but still different. But he did say, from his understanding of it, it seems to be a good case in your favor if handled right.
Have a good day.