Rust Never Sleeps . . .
Oxidation Happens . . .
Agreed, whenever my eye gets to a point to see what lies underneath, it is a bit alarming to see all the non galvanized parts with a coat of rust on them.
These are heavier gauge steel parts though ~ they're not going to " Rust Out " or crumble away like the thin body panels of a Ford from the 1970s; they're beams, arms, brackets, etc. made of Hot Rolled steel that will hold up for a very very long time despite the presence of the unsightly oxidation ~ a natural occurring process to any Carbon ~ Iron Ore derived auto part of piece of manufactured Steel for that matter.
Even an added coat of " tar " will eventually fall off, and oxidation will take place; so don't regret not opting for the " Rusty Jones " or " Ziebart " Dealer Added Profit item to the undercarriage of your INFINITI
Whilst spewing my rebuttal, I'll add commentary on the Trans Fluid ~
My opinion is; if shifting is normal and strong, why monkey with the fluid earlier than need be . . .
Bottom line, the QX50, with it's mighty 325 HP VQHR 3.7 and Down Shift Rev Matching 7 Speed Auto Trans is built on Solid underpinnings . . .
Drive and Enjoy . . .
Worry Less . . and get daily satisfaction knowing your INFINITI is a superior built machine compared to most of the vehicles out there on the road.