As far as TSBs, they pretty much have to witness the symptom.
That's a manufacturer's requirement with every car line/
But if they do, they will fix it at no cost as long as you are in warranty.
If there is a TSB available they will use that as the fix and often as the reason for the fix.
But you cannot (under normal circumstances) go to a dealer and have him perform a TSB on general principles/ They won't do it.
There are no problems (yet) that we know are present in EVERY Murano so they would prefer to perform those free fixes only on vehicles that have the problem.
So rest assured, if you have a problem covered by a TSB, there will be no charge.
If you have a problem not covered by a TSB there will be no charge.
The above is true of course only if the item under discussion is under warranty.
Since yours is a used 03 model, the only thing that will be problematic will be the 12 month items. These are things like "adjustments".
For instance the wheel alignment would likely not be covered.
The consumables likely would not be covered. For instance if the brake pads are worn they would not be covered.
All of this should be covered however
Basic: 3 yr. / 36000 mi.
Drive train: 5 yr. / 60000 mi.
Rust: 5 yr. / Unlimited mi.
If this is not clear, I plead the fact that warranty and TSB can be somewhat convoluted. But for the most part, you bought a near new vehicle that will be covered for almost everything. TSBs or not.
Homer makes an excellent point regarding the application of the TSB. The TSB is not a recall, the dealer will not perform any preventative fix to your vehicle to prevent a potentially bad part from breaking. What the TSB is is an official procedure to address an existing problem area on a particular vehicle if the vehicle is displaying those symptoms.
For example, lets say the Murano has squeaky brakes, and the TSB calls for application of revised brake pads.
Case 1: Your Murano has squeaky brakes. Dealer will under warranty and according to the TSB, replace your squeaky pads with revised quieter pads.
Case 2: You have the older pads but they do not squeak. You take the car to the dealer, saying I want these pads replaced before they squeak. Dealer will NOT replace the pads under warranty, and the TSB does not apply.
Hope that helps people to understand the TSB process.