What's best combo? Given,

A. Self-maintenance
B. Nissan
C. 3rd party

A for 'easy' stuff such as oil changes to avoid pressure wrench induced bolt thread stripping, and other high paced damages

B for TSB events and other 'major' issues as appear, such as timing chain

C for 'regular' minimal issues, where non-specialization not a problem, like
a halogen bulb replacement, or nitrogen tire fillup.

Some may wish to simplify with B only, or if have tons of tools and experience,
A only, using laptop to get codes etc. It might vary with regions ( FL ) .. any comments?

 

If we're talking about a new car, then B for stuff that could affect your warranty. A/C for anything else.

I consider oil changes something that can and does affect your warranty. If you don't have proof (receipts, logs, etc.) of normal preventative maintenance, then if you have a failure of some major engine/trans/etc component, then you CAN be denied warranty service.

Unless you are equiped with a Consult II system, then A-only probably won't work for you. Sometimes, you just have to suck it up and take the car to the dealer.

If you're lucky like most of us, your car will never or rarely see the dealer for any real or serious problems.